Commonwealth v Verwayen

The Application of the Doctrine of Estoppel by Conduct to the Facts of the Present Case

Dawson J.'s analysis of the facts of the present case, which falls within category (a) (and arguably (b) and (d) also) of par. 4 (above), leads, in my view, to the conclusion that, subject to any necessary amendments to the pleadings being allowed and made (as to which see the judgments of Dawson and Gaudron JJ.), the Commonwealth is estopped from disputing its liability to Mr. Verwayen for damages for the injuries he sustained while in its service. In so far as the above numbered paragraphs embody requirements on the path to that conclusion, the requirements of all but pars. 4 and 8 are clearly satisfied. The steps leading to that conclusion which are open to real dispute involve the answers to two related questions: (i) whether, in circumstances where Mr. Verwayen has obtained the benefit of a limited order as to costs, the Commonwealth would be acting unconscionably if it disputed its liability at this late stage (par. 4); and, (ii) whether, in those circumstances, the unqualified operation of the doctrine of estoppel to preclude the Commonwealth from denying liability would be disproportionately burdensome to the Commonwealth and accordingly unjust (par. 8). I add to Dawson J.'s analysis of the facts some supplementary comments of my own to make plain why I consider that those two questions should be respectively answered in the affirmative and in the negative, that is to say, favourably to Mr. Verwayen.

As I followed the argument, it is common ground that Mr. Verwayen's injuries were sustained by reason of the negligence of a person or persons in the service of the Commonwealth. He was, himself, also in that service. Indeed, it is the fact that he was a serving member of the Royal Australian Navy which the Commonwealth now seeks to invoke as a ground for denying that it owed him any duty of care. The other defence which the Commonwealth seeks to invoke is that Mr. Verwayen's action is statute-barred. It is not suggested that the Commonwealth was other than fully conscious of these possible defences when it induced Mr. Verwayen to assume that his action for damages for negligence would proceed against the Commonwealth and be determined on the basis that liability was admitted. With the encouragement of the Commonwealth, there was established between the Commonwealth and Mr. Verwayen the relationship of admitted wrongdoer (the Commonwealth) and wronged (Mr. Verwayen) for the express common purpose of enabling the expeditious assessment of the amount of compensation which the wrongdoer should pay. On the basis of that assumption and relationship, Mr. Verwayen proceeded with the preparation and prosecution of his action. He expended both time and money thereon. Far more important, he subjected himself to the stress, anxiety and inconvenience which were inevitably involved in the pursuit of the proceedings. It was only when the actual hearing was all but due to commence that the Commonwealth sought to depart from the induced assumption and to destroy the whole material relationship between the respondent and itself and the entitlement to just compensation which would result from it.

In the ordinary case where a party to litigation amends a pleading to raise a new defence or to assert a new claim, questions of estoppel do not arise. The effect of earlier pleadings will be merely to reflect the particular party's then intentions in relation to the conduct of the action and the other party will not be justified in assuming that subsequent amendment will not be made. Nor, in such a case, will amendment of the pleadings and subsequent conduct of the proceedings on the basis of the amendment give rise to any suggestion of unconscionable conduct on the part of the amending party. It will involve no more than the exercise of the right to seek to raise additional matters of claim or defence in accordance with the procedures laid down for that purpose. The present case is, however, far removed from the ordinary one. The claimed estoppel does not arise merely from the Commonwealth's failure to deny liability in the pleadings. It arises from the fact that other actions of the Commonwealth constituted an unambiguous representation to Mr. Verwayen that liability would not be contested, that is to say, that a limitations defence would not be relied on and that breach of a duty of care would not be denied. The assumption upon which Mr. Verwayen acted was knowingly and deliberately induced and the resulting material relationship of wrongdoer and wronged was deliberately established so that the action could proceed expeditiously to the assessment of damages. The evidence discloses that the Commonwealth had, to the knowledge of Mr. Verwayen, admitted its liability to pay damages to at least one other injured serviceman in comparable circumstances. The confinement of the dispute to the assessment of damages had, no doubt, the advantage, from the Commonwealth's point of view, that it avoided the public impression of a mean-spirited and technical approach to those injured in the performance of their duties as members of their country's defence forces.

Equity has never adopted the approach that relief should be framed on the basis that the only relevant detriment or injury is that which is compensable by an award of monetary damages. To the contrary, a major part of equity was founded upon a denial of that approach (see, e.g., Pomeroy's Equity Jurisprudence, par. 116; Dougan v. Ley [2] , per Dixon J.; Aristoc Industries Pty. Ltd. v. Wenham Pty. Ltd. [3] ; Doulton Potteries Ltd. v. Bronotte [4] ). If the Commonwealth were now allowed to depart from the assumed state of affairs, the detriment which Mr. Verwayen would sustain could not be measured in terms merely of wasted legal costs. The past stress, anxiety, inconvenience and effort which were involved in the pursuit of the proceedings would be rendered futile. More important, Mr. Verwayen would be subjected to the potentially devastating effects of a last-minute denial of an expectation of just compensation for his injuries in circumstances where those injuries were sustained in the course of the service of the Commonwealth by reason of the negligence of another or others in that service and where that expectation of just compensation had been deliberately induced by the Commonwealth. In that regard, the learned primary judge was expressly informed, without objection or dissent, that the relevant detriment included "increased ill health" and that part of Mr. Verwayen's "problems are of a psychiatric nature and medical evidence is that this" - i.e. the Commonwealth's inducement of the assumption and attempt to depart from it ("take away the carrot") - "has had and will continue to have severe consequences upon the ill health produced by the defendant's negligence" (i.e. the original accident). It is true that the extent of the detriment which, in the absence of an estoppel, Mr. Verwayen would sustain by reason of the induced assumption has not been established or quantified with the precision which might be thought necessary to discharge an onus of proof in an action for pecuniary compensation for that detriment. That is not surprising however, since the issue of estoppel was resolved against Mr. Verwayen before he had an opportunity of leading detailed evidence. More important, the absence of such detailed evidence is not really to the point in circumstances where the relevant detriment to Mr. Verwayen would obviously extend far beyond any question of legal costs and be of such a nature and extent that it cannot properly be said that it exceeds the requirements of good conscience or is unjust to the Commonwealth to hold it to the assumed state of affairs upon the basis of which it deliberately induced Mr. Verwayen to act.

1. (1946) 71 C.L.R. 142, at p. 150. 2. [1965] N.S.W.R. 581, at pp. 587-588. 3. [1971] 1 N.S.W.L.R. 591, at p. 597.

There are three further matters which I would mention. The first is, to some extent, a matter of semantics. It is that I do not see the case as one of "waiver". In Foran v. Wight [5] , I expressed the view that the somewhat arbitrary doctrine of waiver is being increasingly absorbed and rationalized by the more flexible doctrine of estoppel by conduct and that, "in cases where the focus is upon action by one party "upon" what was conveyed to that party by the other party, the applicable primary doctrine should be seen in a modern context as that of estoppel". Upon reflection, I should have omitted the qualification "primary" from that statement. In the context of the development of the general doctrine of estoppel by conduct in recent years, it seems to me to be preferable to confine the rubric of "waiver" within the area of the law in which, notwithstanding the absence of consideration, the act of the alleged waivor is of itself directly operative to "waive" a right or entitlement without there being any need to establish that the other party has acted upon the basis that the right or entitlement in question was no longer asserted. The principal examples of cases falling within that area are cases of true election (see, generally, the discussion in the judgment of Lord Goff of Chieveley in The "Kanchenjunga" [6] ). Where a case is said to fall within that area, estoppel by conduct may, if the claim of waiver fails, operate either directly to preclude enforcement of the right allegedly waived or indirectly to preclude departure from a representation that the right had been or would be waived. Even if I had (like Gaudron J.) seen the present case as falling within a category where, in the context of a change of relationship, detriment could be assumed, it would not, in my view, be one in which any particular act or acts of the Commonwealth of themselves operated as a waiver of the relevant defences. That being so, I have identified the applicable doctrine solely in terms of estoppel by conduct. The second further matter is that, as I followed the argument, the Commonwealth adopted the position that, if it fails (as I think it does) in its argument in this Court on the question of estoppel on the basis of the material at present in evidence, that question should be finally determined against it. The final matter which I would mention is that, if I had been of the view that the material presently in evidence was inadequate to found a conclusion that Mr. Verwayen's relevant detriment extended beyond his liability in respect of legal costs and outgoings, I would have considered that he should, in all the circumstances of the case, be given an opportunity to apply for an order that would enable him to lead further evidence in relation to that matter. As I have indicated, perusal of the transcript of argument before the learned primary judge discloses that the proceedings at first instance were conducted on the basis that, for the purposes of a consideration of the question of estoppel as a preliminary point, it was unnecessary that Mr. Verwayen lead evidence to establish the allegation (made in further and better particulars) that the relevant detriment extended beyond liability for costs and included "increased stress as a result of continued protraction of these proceedings leading to an aggravation of his psychiatric state of health". It also discloses that determination of the question of estoppel as a preliminary point was contrary to the wishes of Mr. Verwayen and that a somewhat informal approach was taken to the identification of what was and was not in evidence before his Honour for the purposes of that determination. In these circumstances, it appears to me that, if the material in evidence had proved inadequate to establish detriment beyond liability for legal costs, the interests of justice would have required that Mr. Verwayen be afforded an opportunity of applying for an order that would have allowed him to supplement that evidence either on further hearing of the preliminary point before the trial judge or, as the Full Court would seem to have thought appropriate in an earlier appeal from an interlocutory order made in the case, before the jury on the trial.

1. (1989) 168 C.L.R. 385, at pp. 433-435. 2. [1990] 1 Lloyd's Rep. 391, at pp. 397-400. Dawson J.

The circumstances of this appeal are sufficiently set out elsewhere. The respondent (the plaintiff in the action) pleaded in reply that the Commonwealth has waived, or is estopped from relying upon, a defence under s. 5 of the Limitation of Actions Act 1958 Vict. raised by it by amendment of its defence. The respondent also pleaded in reply that the Commonwealth has waived a defence raised by it by amendment that, because the respondent was injured, if at all, whilst participating in combat exercises as a serving member of the Royal Australian Navy, the Commonwealth owed him no duty of care.

In argument, the respondent did not draw any clear distinction between waiver and estoppel. Indeed, authority favours the view that, in the present context, no such distinction can in principle be drawn. "Waiver" is an imprecise term and is used to describe what is done in a variety of circumstances rather than to assert any particular legal process. However, where it is not used in the sense of election between mutually exclusive alternatives, if it has any identifiable legal consequence, it is generally indistinguishable from estoppel. Isaacs J. made this point in a well-known passage in Craine v. Colonial Mutual Fire Insurance Co. Ltd. [7] , where, in delivering the judgment of the Court, he used the word "waiver" in the sense of waiver by election and said that waiver requires a distinct act done with knowledge and intention in order to see whether there has been an election. Waiver looks "chiefly to the conduct and position of the person who is said to have waived, in order to see whether he has "approbated" so as to prevent him from "reprobating" - in English terms, whether he has elected to get some advantage to which he would not otherwise have been entitled, so as to deny to him a later election to the contrary".

Isaacs J. contrasted election with the doctrine of estoppel by conduct which, he said [8] , "looks chiefly at the situation of the person relying on the estoppel" with the consequence that "the knowledge of the person sought to be estopped is immaterial". He concluded [9] that "estoppel may be established where waiver cannot, and conversely waiver may be found where estoppel does not exist".

1. (1920) 28 C.L.R., at p. 327. 2. (1920) 28 C.L.R., at p. 328.

The passage from the judgment of Isaacs J. to which I have referred is cited in Spencer Bower and Turner, The Law Relating to Estoppel by Representation, 3rd ed. (1977), pp. 318-319. The authors comment, at pp. 319-320, that:

The truth is, perhaps, that whereas a fairly successful attempt may be made to state with precision what is meant by "estoppel" and by "election", the term "waiver" when used in a similar connotation is not capable of exact definition in the light of the authorities. The authors here refer to Ewart, Waiver Distributed (1917) where, at p. 5, it is said of waiver: "No one has been able to give it satisfactory definition, or to assign to it explanatory principles. The word is used indefinitely as a cover for vague, uncertain thought." Spencer Bower and Turner continue, at p. 320: Possibly it may be regarded as usefully describing an end-result; but its application to the process by which that result is brought about is almost invariably attended with ambiguity as to the essential nature of that process. The term when so employed is used sometimes in one significance and sometimes in another, and the result is that its use has dangers which may be avoided only by foregoing it as a useful term when considering either estoppel or election. When it does appear in the authorities, however, it is submitted that it will more probably be found to connote "election" than "estoppel" - and for the reasons which have so well been expressed by Isaacs J.

In Kammins Ballrooms Co. Ltd. v. Zenith Investments (Torquay) Ltd. [10] , Lord Diplock also distinguished waiver amounting to an election from waiver amounting to an estoppel. The former, he said, occurs where "a person is entitled to alternative rights inconsistent with one another" and "acts in a manner which is consistent only with his having chosen to rely on one of them". The latter "debars a person from raising a particular defence to a claim against him" and "arises when he either agrees with the claimant not to raise that particular defence or so conducts himself as to be estopped from raising it". In referring to waiver amounting to estoppel, Lord Diplock was speaking not only of estoppel by conduct which is based upon a representation or an assumption with respect to an existing state of affairs. He was also speaking of promissory or equitable estoppel which is based upon an assumption with regard to future conduct. The assumption may arise from a representation or from conduct - that is to say, it may be the result of an express or implied promise. See also The "Kanchenjunga" [11] .

1. [1971] A.C. 850, at p. 883. 2. [1990] 1 Lloyd's Rep. 391.

Of course, when Isaacs J. spoke about estoppel in Craine v. Colonial Mutual Fire Insurance Co. Ltd., he was confining his observations to estoppel by conduct. As he said in Ferrier v. Stewart [12] , "estoppel has reference to an existing fact, and not to a promise de futuro, which must rest, if at all, on contract". But the law has developed considerably since Isaacs J. made his observations and promissory estoppel within its proper confines is no longer seen as a threat to the doctrine of consideration. A limited form of promissory estoppel had never entirely disappeared from the law of equity and, therefore, the development has taken place in that area. But, as was recognized in Waltons Stores (Interstate) Ltd. v. Maher [13] , the basic considerations underlying both common law estoppel and equitable estoppel have always been the same. The only thing standing in the way of their parallel development has been the persistence of the view at common law that to succumb to a doctrine of promissory estoppel would be to undermine the foundations of the law of contract. Yet the description of estoppel by conduct given by Dixon J. in Thompson v. Palmer [14] and Grundt v. Great Boulder Pty. Gold Mines Ltd. [15] is equally applicable to common law estoppel and equitable estoppel. The description appearing in Thompson v. Palmer [16] is as follows:

The object of estoppel in pais is to prevent an unjust departure by one person from an assumption adopted by another as the basis of some act or omission which, unless the assumption be adhered to, would operate to that other's detriment. Whether a departure by a party from the assumption should be considered unjust and inadmissible depends on the part taken by him in occasioning its adoption by the other party. The "unjust departure from an assumption" of which Dixon J. speaks is equally applicable to an assumption with respect to future conduct as an assumption with respect to an existing state of affairs and the requirement that the departure must be unjust may be taken as a reference to the unconscionable conduct required to found an equitable or promissory estoppel. It is the requirement of unconscionable conduct which is now seen as the protection against undue intrusion upon the law of contract, for a voluntary promise of itself will not give rise to an estoppel. An estoppel will occur only where unconscionable conduct on the part of one gives rise to an equity on the part of another. The estoppel will then operate to take account of that equity. 1. (1912) 15 C.L.R. 32, at p. 44. 2. (1988) 164 C.L.R. 387. 3. (1933) 49 C.L.R. 507. 4. (1937) 59 C.L.R. 641. 5. (1933) 49 C.L.R., at p. 547.

How exactly the estoppel will operate to take account of that equity is another question. The result of an estoppel at common law was, viewed as a separate and distinct doctrine from equitable estoppel, to preclude the party estopped from denying the assumption upon which the other party acted to his detriment. It followed that the party who acted to his detriment was, in effect, given the benefit of the assumption. It was all or nothing. By contrast, the view is expressed by Mason C.J. and Wilson J. and by Brennan J. in Waltons Stores (Interstate) Ltd. v. Maher [17] respectively, that an estoppel in equity may not entitle the party raising it to the full benefit of the assumption upon which he relied. The equity is said "not to compel the party bound to fulfil the assumption or expectation; it is to avoid the detriment which, if the assumption or expectation goes unfulfilled, will be suffered by the party who has been induced to act or to abstain from acting thereon" [18] , per Brennan J. To avoid the detriment may, however, require that the party estopped make good the assumption: see Crabb v. Arun District Council [19] ; Ramsden v. Dyson [20] , per Lord Kingsdown; Jones (A.E.) v. Jones (F.W.) [21] ; Riches v. Hogben [22] . But, depending upon the circumstances of the case, the relief required may be considerably less.

1. (1988) 164 C.L.R., at pp. 404-405, 423. 2. (1988) 164 C.L.R., at p. 423. 3. [1976] Ch. 179, at pp. 190, 192, 199. 4. (1866) L.R. 1 H.L. 129, at p. 170. 5. [1977] 1 W.L.R. 438, at p. 443; [1977] 2 All E.R. 231, at p. 236. 6. [1985] 2 Qd R. 292, at p. 302.

If this view is right, estoppel at common law and in equity may have had common origins, but there the similarity stops. While the role of estoppel at common law was largely as a rule of evidence, its role has been vastly expanded in equity to raise questions of substance. At the same time, the discretionary nature of the relief in equity marks a further reason why the fear of the common law that promissory estoppel would undermine the doctrine of consideration is unwarranted. In this case, in view of the conclusion which I have reached as to the relief to which the respondent is entitled, it is not necessary to carry this aspect of the matter any further.

Nevertheless, the development of the equitable doctrine has been cautious. In Legione v. Hateley [23] , this Court held that promissory estoppel should be accepted in Australia as applicable to parties in a pre-existing contractual relationship. That is to say, it was held that it should be accepted that a person who has a contractual right may be estopped from enforcing it if he has made representations or has so conducted himself as to lead to an assumption by the other party that he does not intend to enforce it. He may be estopped from departing from the assumption if the departure would amount to unconscionable conduct and would operate to the detriment of the other party by reason of his having conducted himself in reliance upon the assumption. In Legione v. Hateley, since the parties were in a pre-existing contractual relationship, it was unnecessary to consider whether the doctrine of promissory estoppel should be accepted as a general doctrine applicable regardless of that relationship. That consideration arose in Waltons Stores (Interstate) Ltd. v. Maher and the further step was taken. A pre-existing contractual relationship was held not to be a prerequisite to the application of the doctrine of promissory estoppel. As I have said, the protection of the law of contract was seen to lie in the requirement of unconscionable conduct and the discretionary nature of the relief.

But it is, I think, unnecessary to go beyond Legione v. Hateley for the purposes of this case. For the parties here, whilst not in a contractual relationship, were in a legal relationship which began at least with the commencement of the action by the respondent against the appellant. It may well be that legal relations arose between the parties at an earlier stage upon the commission of the tort alleged by the respondent, but it is unnecessary to go back any further than the commencement of the action. Whilst the cases speak of pre-existing contractual relations, there is no reason why the doctrine of promissory estoppel, even in the restricted form recognized in Legione v. Hateley, should be confined to cases where the pre-existing legal relationship arose from contract. That was the view taken by Donaldson J. in Durham Fancy Goods Ltd. v. Michael Jackson (Fancy Goods) Ltd. [24] , and it appears to me to be plainly correct. See also Waltons Stores (Interstate) Ltd. v. Maher [25] , per Mason C.J. and Wilson J.; The "Henrik Sif" [26] . In this case, the parties were in a relationship which gave rise to legal rights and duties with regard to one another; it was a legal relationship. One of the appellant's rights was the statutory right to bar the respondent's action by insistence upon the statute of limitations. If by its conduct the appellant caused the respondent to assume that it would not exercise that right, and departure by the appellant from that assumption would be unconscionable and would operate to the detriment of the respondent by reason of his having acted or omitted to act upon the basis of the assumption, there is no reason why the appellant should not be estopped from insisting upon the statute.

1. [1968] 2 Q.B. 839, at p. 847. 2. (1988) 164 C.L.R., at p. 399. 3. [1982] 1 Lloyd's Rep. 456, at p. 466.

It is commonly said that a person may waive a statutory right in the sense of not relying upon it. In order to waive a statutory right in this way, it must be a personal or private right and must not rest upon public policy or expediency: see Brown v. The Queen [27] . Provided that it bars a remedy rather than extinguishes a cause of action, a statute of limitations gives rise to a right of that kind and it must be pleaded if it is to be invoked: Re Burge; Gillard v. Lawrenson [28] . If it is not pleaded, it is said to be waived, but the use of the term "waiver" in this way exemplifies its imprecision. A waiver of this kind does not amount to an election and does not necessarily give rise to an estoppel.

1. (1986) 160 C.L.R. 171, at p. 208. 2. (1887) 57 L.T. 364.

A defendant who fails to plead a period of limitation may apply for leave to amend his defence to enable him to do so. The appellant did that in this case and was granted leave. The considerations which govern a decision to grant or refuse leave to amend are of a different kind from those which go to establish an estoppel. The rules of court have always provided that leave to amend pleadings may be given for the purpose of determining the real question in controversy between the parties (see now O. 36, r. 1 of the Supreme Court Rules (Vict.)) and an amendment should ordinarily be allowed if any harm arising from so doing can be compensated for by the imposition of terms upon the party asking for the amendment: see Shannon v. Lee Chun [29] ; Tildesley v. Harper [30] ; Cropper v. Smith [31] . The usual terms which are imposed are an order for costs or an adjournment. In granting leave to amend, a court is concerned with the raising of issues and not with their merits. Of course, an amendment which is futile because it is obviously bad in law will not be allowed. But it is no ground for refusing an amendment that it raises a claim or defence which ought not to succeed. That will be an issue upon trial. An amendment may, however, be refused because it is made at such a late stage that neither costs nor an adjournment can compensate the other side for the failure to raise the issue at an earlier stage. In Ketteman v. Hansel Properties Ltd. [32] the House of Lords considered an application for amendment which had been made at the stage of final addresses. It was an application to amend in order to raise a defence under a statute of limitations. Lord Griffiths observed [33] :

I have never in my experience at the Bar or on the Bench heard of an application to amend to plead a limitation defence during the course of the final speeches. Such an application would, in my view, inevitably have been rejected as far too late. A defence of limitation permits a defendant to raise a procedural bar which prevents the plaintiff from pursuing the action against him. It has nothing to do with the merits of the claim which may all lie with the plaintiff; but as a matter of public policy Parliament has provided that a defendant should have the opportunity to avoid meeting a stale claim. The choice lies with the defendant and if he wishes to avail himself of the statutory defence it must be pleaded. A defendant does not invariably wish to rely on a defence of limitation and may prefer to contest the issue on the merits. If, therefore, no plea of limitation is raised in the defence the plaintiff is entitled to assume that the defendant does not wish to rely upon a time bar but prefers the court to adjudicate on the issues raised in the dispute between the parties. If both parties on this assumption prepare their cases to contest the factual and legal issues arising in the dispute and they are litigated to the point of judgment, the issues will by this time have been fully investigated and a plea of limitation no longer serves its purpose as a procedural bar. 1. (1912) 15 C.L.R. 257. 2. (1878) 10 Ch. D. 393, at pp. 396-397. 3. (1884) 26 Ch. D. 700, at p. 710. 4. [1987] A.C. 189. 5. [1987] A.C., at p. 219.

In this case, the appellant having amended its defence to plead the statute of limitations and the respondent having pleaded waiver or estoppel, an issue was raised for trial. But the issue raised was one of estoppel rather than of waiver in some other sense. When the term "waiver" is not being used to describe election or estoppel it may be used loosely to indicate non-insistence upon a right either by choice or by default. The use of the term in that sense raises a different question, namely, whether a party, having failed to insist upon his right at an appropriate time, should later be allowed to do so. In this case, that question was determined when the appellant was given leave to amend its defence. In a case such as Ketteman v. Hansel Properties that was the question for determination. Sometimes the questions of estoppel and of waiver in this loose sense are not kept distinct. Wilson v. McIntosh [34] is an example. In that case an applicant to bring lands under the New South Wales Real Property Act 1862 (26 Vict. No. 9) filed a case in the Supreme Court more than three months after a caveat had been lodged. He thereafter obtained an order that the caveator should file her case. The Privy Council held that the applicant had thereby waived his right to have the caveat set aside as lapsed for non-activity on the part of the caveator during the period of three months. In so holding it relied upon a passage from the judgment of Darley C.J. in a similar case, Phillips v. Martin [35] , where he said:

Here there is abundant evidence of waiver, and it is quite clear that a man may by his conduct waive a provision of an Act of Parliament intended for his benefit. The caveator was not brought into Court in any way until the caveat had lapsed. And now the applicant, after all these proceedings have been taken by him, after, doubtless, much expense has been incurred on the part of the caveator, and after lying by and hoping to get a judgment of the Court in his favour - asks the Court to do that which but for some reasons known to himself he might have asked the Court to do before any other step in the proceedings had been taken. I think he is altogether too late. It is to my mind a clear principle of equity, and I have no doubt there are abundant authorities on the point, that equity will interfere to prevent the machinery of an Act of Parliament being used by a person to defeat equities which he has himself raised, and to get rid of a waiver created by his own acts. 1. [1894] A.C. 129. 2. (1890) 11 N.S.W.L.R. 153, at p. 158.

Clearly the question in both Wilson v. McIntosh and Phillips v. Martin was whether the applicant should be allowed to raise the issue of the lapse of the caveat, rather than whether that issue, if raised, should be determined in favour of one or other of the parties. They were not, therefore, cases in which the issue of lapse was raised and met by a plea of estoppel. Perhaps if the issue had been raised such a plea may have been successful, but that was not the question. Nevertheless, the terms "waiver" and "estoppel" were used interchangeably. Thus in Phillips v. Martin [36] , Innes J. expressed the view that it was rightly admitted by counsel for the applicant "that if anyone could be estopped from taking advantage of this Act that his client should be estopped in this particular case" and Foster J. said [36] that "the applicant is estopped from taking that point at this stage of the case".

1. (1890) 11 N.S.W.L.R., at p. 159. 2. (1890) 11 N.S.W.L.R., at p. 159.

But the distinction between being allowed to raise an issue and the determination of an issue once raised is important because the two things are governed by different considerations. The distinction is more easily observed in the context of pleadings but is by no means confined to that situation. Quite commonly a point which is not a pleading point is not taken by a party to litigation when it arises and he is said to have waived it with the consequence that it cannot be raised at a later stage. A recent example is to be found in Vakauta v. Kelly [37] , which held that a party's right to object to the participation of a judge in the proceedings on the ground of ostensible bias had been waived as it had not been raised at the appropriate time.

In this case, by pleading waiver the respondent was not asserting that the appellant had lost the opportunity to plead the statute of limitations. Obviously, having been given leave to amend, it had not. Rather, the respondent was seeking to have the issue which was raised by the amended pleadings determined; he was seeking to have the appellant estopped from relying on the statute.

Although it was the respondent, the plaintiff in the action, who was seeking to have the appellant estopped, he was not doing so in a manner which was inconsistent with its defensive character. In Foran v. Wight [38] , there is an observation that, even upon the traditional view: "a plaintiff may rely upon an estoppel if he has an independent cause of action and the estoppel upon which he relies is in answer to a defence raised by the defendant rather than part of the cause of action itself: see Waltons Stores (Interstate) Ltd. v. Maher [39] ." And in Waltons Stores (Interstate) Ltd. v. Maher [40] Deane J., said:

It has often been said that estoppel can be used only as a shield and not as a sword. In so far as estoppel by conduct is concerned, that statement is generally true only in the very limited sense that such an estoppel operates negatively to preclude the denial of, or a departure from, the assumed or promised state of affairs and does not of itself constitute an independent cause of action. The authoritative expositions of the doctrine of estoppel by conduct to be found in judgments in this Court have been consistently framed in general terms and lend no support for a constriction of the doctrine in a way which would preclude a plaintiff from relying upon the assumed or represented mistaken state of affairs (which a defendant is estopped from denying) as the factual foundation of a cause of action arising under ordinary principles of the law 1. (1989) 170 C.L.R. 385, at p. 450. 2. (1988) 164 C.L.R., at p. 400. 3. (1988) 164 C.L.R., at pp. 444-445.

What Deane J. is saying in that passage, as I understand it, is that a plaintiff may rely upon an estoppel, even in the formulation of his claim, if his cause of action is not one in which estoppel is an ingredient, however much estoppel may assist him in an evidentiary way in establishing his cause of action. Indeed, this case is a good illustration of the point. The respondent was in no position to rely upon an estoppel at the time he formulated his claim. The estoppel arose at a later stage and was pleaded in reply. A reply is obviously of a defensive character. Yet if the estoppel had arisen before the respondent commenced his action, he may have relied upon it as part of his claim, although his cause of action would still have been negligence, of which estoppel forms no part.

There can be no doubt that the appellant's conduct resulted in the adoption of an assumption on the part of the respondent. The respondent was plainly led to assume that the appellant would not raise a defence of limitation. Nor, to my mind, is there any doubt that the departure from that assumption by the appellant was unconscionable. It was not a case in which the adoption of the assumption by the respondent was occasioned merely by the initial absence of any plea raising the defence or by a mere promise not to raise it.

It was the result of a deliberate course of action on the part of the appellant pursued consistently over a considerable period of time. See The "Henrik Sif" [41] . Moreover, it is significant that it was a course of action not confined to the respondent but extending to survivors of the Voyager collision in general. As the Minister for Defence stated in a letter in August 1985: "the Commonwealth has acted consistently with its past practice in regard to VOYAGER claimants in admitting negligence (in the legal sense) and the Commonwealth has never relied upon the absolute defence open to it by reason of the expiration of the statutory limitation periods in regard to claims by VOYAGER survivors." The solicitors who acted for the respondent also acted for many other survivors of the Voyager collision. Before commencing this action on behalf of the respondent, they had been engaged in correspondence with the solicitors acting for the Commonwealth and with the Minister for Defence himself in relation to an action brought on behalf of another Voyager survivor. In that action, they had requested that the Commonwealth not rely on the limitation defence. Both the solicitors acting for the Commonwealth and the Minister for Defence gave written assurances that the Commonwealth would not insist on its rights under the Limitation of Actions Act. In addition, from November 1983 conversations took place, usually on a weekly basis and usually by telephone, between the solicitors for the plaintiff in that action and the Commonwealth's legal representatives to the effect that the Commonwealth had agreed not to plead the statute. Before the respondent issued his writ in November 1984 his solicitors sought an assurance during September on behalf of the respondent and four other survivors of the Voyager collision that, in the light of the Commonwealth's treatment of the plaintiff in the previous action, "you treat these men the same and waive the Statute to allow us to proceed on their behalf". Although the formal assurance was not received until after the respondent's writ had been issued, it is a fair inference that he would not have commenced his action had he not expected, in the light of the treatment afforded his fellow servicemen, to receive the assurance he sought.

His expectation was met with an assurance that the statute would be waived. The respondent's delay in commencing the action was explicable upon reasonable grounds and the appellant's decision not to insist upon the period of limitation and to contest the case on its merits could readily be seen as prompted by a humane attitude befitting the Commonwealth towards a former member of its armed services. The appellant continued to encourage the respondent in his belief that there would be no insistence upon the statute by joining in applications for an expedited hearing and, a year after the commencement of the action, by reiterating that it would "not [be] pressing the statutory limitation period as a defence". The subsequent abrupt change in policy on the part of the appellant, unexplained as it was, constituted the breach of a firm assurance deliberately given on more than one occasion over a considerable period of time. The absence of any attempt by the appellant to justify the amendment to its defence, other than upon the basis that it was entitled to take the course which it did, leads inevitably to the conclusion that in conscience it was unable to do so, having stood by for so long whilst the respondent pursued his claim upon the basis that he was assured of success, subject only to the proof of damage.

There can be no question that the respondent acted upon the assumption that the appellant would not exercise its right to claim that the action was statute barred. No doubt the respondent was, or could be, compensated by an award of costs for any actual expense incurred as a result of the appellant's failure to plead the statute of limitations at the beginning. But the real detriment to the respondent was that he was induced by the assumption that the appellant would not insist upon the statute to allow the litigation to proceed for more than a year without taking any steps to bring it to a conclusion by way of settlement or, if necessary, withdrawal. Furthermore, as Lord Griffiths observed in Ketteman v. Hansel Properties [42] , "justice cannot always be measured in terms of money" and the strain of litigation, particularly where that litigation is between a natural person and a defendant with the resources of the Commonwealth, is not to be underestimated. By falsely raising his hopes, the appellant led the respondent to continue with the litigation and forgo any exploration of the possibility of settlement thereby subjecting himself to a prolonged period of stress in an action in which the damages claimed were for, amongst other things, a high level of anxiety and depression. I would hold that the appellant was estopped from insisting upon the statute of limitations, and would observe that the equity raised by the appellant's conduct was such, in my view, that it could only be accounted for by the fulfilment of the assumption upon which the respondent's actions were based; cf. Robertson v. Minister of Pensions [43] .

1. [1987] A.C., at p. 220. 2. [1949] 1 K.B. 227.

The other defence raised by amendment which is said in reply to have been waived is that which alleges that the appellant owed the respondent no duty of care because he was injured, if at all, whilst participating in combat exercises as a serving member of the Royal Australian Navy. In fact, the appellant also amended its defence to deny negligence altogether in addition to denying the existence of a duty of care. It is difficult to understand why the respondent restricted his allegation of waiver to the more limited denial of liability, but in the absence of any amendment of the reply, that is the basis upon which we must deal with the matter. In my view, the appellant was estopped from denying any duty of care for the same reasons as it was estopped from insisting upon the statute of limitations. The two matters were clearly linked in causing the respondent to act or refrain from acting as he did. There was no more justification in the circumstances for the appellant's ultimate denial of liability than there was for its insistence upon the statute. The fact that the litigation was allowed to continue for as long as it did was no doubt due as much to the admission of liability as to the absence of any insistence upon the statute.

Furthermore, any estoppel raised here is also raised defensively rather than as part of the cause of action. Obviously, the cause of action as pleaded by the respondent in his statement of claim involved no estoppel. When the appellant made an admission of liability in its defence, the respondent was relieved, subject to proof of damage, of any obligation to prove negligence. It was by way of defence against the change brought about by the appellant's amendment of its pleading that the respondent raised the question of waiver in reply. The waiver, or estoppel, was not pleaded as part of the cause of action but to preclude the appellant from departing from the assumption which it had induced. I would hold that the appellant was also estopped from denying liability by claiming that it owed no duty of care to the respondent and, for that reason, it is unnecessary to consider further that particular defence.

I would dismiss the appeal. That is the order favoured by a majority of the Court. Its effect will be that the order made by the Full Court of the Supreme Court will stand and that the proceedings will be remitted for trial by jury on the issues of negligence and damages. Having had the advantage of reading the reasons for judgment of Deane, Toohey and Gaudron JJ., that is the appropriate result on the present state of the pleadings, notwithstanding that Toohey and Gaudron JJ. reach their conclusion upon the basis of waiver and Deane J. and I reach our conclusion upon the basis of estoppel. Of course, if (as one would expect) the respondent seeks, and is granted, leave to amend his reply to raise estoppel and waiver in relation to the denial of liability by the appellant (and not just the denial of a duty of care as at present), then, upon the basis of the views expressed by the majority (for whom I am able to speak on this point), the trial will proceed as an assessment of damages only.

The circumstances giving rise to this appeal appear in the judgments of other members of the Court.

A convenient starting point is the application by the Commonwealth on 22 May 1986 to amend its defence. At that time Mr. Verwayen's action had been on foot since 2 November 1984; it was commenced well out of time. The Commonwealth's advisers had told Mr. Verwayen's advisers on 25 January 1985 that the Commonwealth proposed to admit liability for his claim and to waive the Statute of Limitations. The relevant legislative provision was s. 5(6) of the Limitation of Actions Act 1958 Vict. ("the Limitation Act"). Consistent with that advice, on 14 March 1985 the Commonwealth had filed its defence to the action, admitting all the allegations in the statement of claim, save those relating to injuries, loss and damage. It contained no plea that the action was statute barred. It was therefore the not uncommon situation of a defendant admitting liability for the plaintiff's claim but putting in issue the damages to which the plaintiff is entitled.

Thereafter, during 1985, the Australian Government Solicitor had joined on five occasions in applications made on behalf of Mr. Verwayen for an expedited hearing of the only issue arising on the pleadings, namely, the assessment of damages, and had signed a Certificate of Readiness for assessment of damages only. As late as 27 November 1985, the Minister Assisting the Minister for Defence had written to Mr. Verwayen, repeating that "the Commonwealth has admitted negligence and is not pressing the statutory limitation period as a defence". At the same time the Minister expressed regret at "any delay in the finalization of claims". Six months later and only a short time before the assessment of damages was due to take place, the Commonwealth applied for leave to amend its defence.

Against opposition from Mr. Verwayen's counsel, leave was granted to amend the defence so as to deny negligence and to plead, not only s. 5 of the Limitation Act, but also that by reason of the fact that the Voyager and the Melbourne were, at the relevant time, engaged in combat exercises, no duty of care was owed to Mr. Verwayen. I propose to deal first with the limitations issue. Now, it is true that different considerations apply in deciding whether a party should have leave to amend a pleading and in determining the issue raised by the amended pleading, if leave be given. Leave to amend is ordinarily given, even at a late stage, so long as this can be done "without injustice to the other party", to use the words of Bowen L.J. in Cropper v. Smith [44] . See also Shannon v. Lee Chun [45] ; Clough v. Frog [46] ; Atkinson v. Fitzwalter [47] . Nevertheless, it is appropriate to refuse leave to amend, if to grant leave may bring about an injustice to the other party which cannot be compensated by an adjournment or by an order for costs. This is not something that can always be determined by reference to the merits of the matter sought to be raised by the proposed amendment: Strauss v. Douglas Aircraft Co. [48] . There may be cases, and a plea of limitations is a good example, where the amendment proposed has every prospect of success but comes at such a late stage that, if it be granted and the point raised succeeds, an award of costs in favour of the other party is no adequate compensation. It may be, for instance, that it is then too late for the plaintiff to bring action against anyone else: see Joint Coal Board v. Adelaide S.S. Co. Ltd. [49] . It should not be lightly assumed that the "healing medicine" (the words are those of Bowen L.J. in Cropper v. Smith [50] ) of costs is always a sufficient cure for the disadvantage to the other side. Lord Griffiths made the point in Ketteman v. Hansel Properties Ltd. [51] when he said:

Whether an amendment should be granted is a matter for the discretion of the trial judge and he should be guided in the exercise of the discretion by his assessment of where justice lies. Many and diverse factors will bear upon the exercise of this discretion. I do not think it possible to enumerate them all or wise to attempt to do so. But justice cannot always be measured in terms of money and in my view a judge is entitled to weigh in the balance the strain the litigation imposes on litigants, particularly if they are personal litigants rather than business corporations, the anxieties occasioned by facing new issues, the raising of false hopes, and the legitimate expectation that the trial will determine the issues one way or the other. 1. (1884) 26 Ch. D. 700, at p. 710. 2. (1912) 15 C.L.R. 257, at p. 261. 3. (1974) 48 A.L.J.R. 481; 4 A.L.R. 615. 4. [1987] 1 W.L.R. 201, at pp. 204-205; [1987] 1 All E.R. 483, at pp. 485-486. 5. (1968) 404 F. 2d 1152, at p. 1155. 6. [1964] N.S.W.R. 1126. 7. (1884) 26 Ch. D., at p. 711. 8. [1987] A.C. 189, at p. 220.

Therefore, while it is true that to grant the amendment sought by the Commonwealth would not preclude Mr. Verwayen, by some such plea as waiver or estoppel, from meeting the matters raised by the amendment, the delay in seeking to plead limitations, particularly in the context of the many assurances given to Mr. Verwayen by the Commonwealth that no such plea would be raised against his claim and that liability would be admitted, provided compelling reasons for refusing leave to amend. However, there was no appeal from the order giving the Commonwealth leave to amend its defence and the matter must be approached on the basis that the amended defence has been properly entered. To that defence Mr. Verwayen pleaded by way of reply that the Commonwealth "agreed to and did waive any such defence". That plea went to the defence that no duty of care was, in the circumstances, owed to Mr. Verwayen and also to the defence based on s. 5 of the Limitation Act. In addition, the reply asserted that the Commonwealth was "estopped" from relying upon either defence. However, the reply did not advert to the general denial of negligence, a matter that is referred to again at the end of these reasons.

Putting to one side for a moment the terminology of waiver or estoppel, it is necessary to ask - what is Mr. Verwayen's complaint by reason of the introduction of the new matters into the Commonwealth's defence? One thing is clear, he cannot complain that, by reason of anything done or not done by the Commonwealth, he was induced to delay bringing his action until after the relevant limitation period had expired. As already mentioned, the limitation period had expired well before there was any communication between Mr. Verwayen or his advisers on the one hand and the Commonwealth or its advisers on the other. Nor can he complain that he was induced to bring proceedings when he did because of any assurance given by the Commonwealth. It is true that two months earlier his solicitors had written to the Department of Defence on his behalf and on behalf of four other survivors from the Voyager, noting that in the case of another survivor the Commonwealth had "waived the Statute of Limitations" and had "admitted liability". But, by 2 November 1984, no reply had been received to that letter, other than an acknowledgment of receipt and a statement that the request to "treat these men the same" had been referred to the Australian Government Solicitor in Victoria, who would advise the solicitors of the Commonwealth's position.

On the other hand, it is equally clear that the conduct of the Commonwealth, beginning with its advice of 25 January 1985 and continuing until the letter of 27 November 1985, written by the Minister Assisting the Minister for Defence, and thereafter, induced Mr. Verwayen to continue with his action in the belief that liability for his claim was admitted and ultimately to prepare for an assessment of damages, expected to be held during the Wangaratta sittings of the Supreme Court of Victoria to begin on 3 June 1986. When Mr. Verwayen brought his action, it was open to the Commonwealth to include in its defence those matters which it later included, pursuant to the order of 29 May 1986, made on the application of 22 May 1986. It did not do so. Neverthless it might, at any time before May 1986, have sought leave to amend its defence to raise those matters. It did not do so. Furthermore, it engaged in correspondence with Mr. Verwayen's solicitors that left no doubt that it did not propose to rely upon any defence of limitations or indeed upon any defence at all, other than to put Mr. Verwayen to proof of damage.

It is against that background that it is necessary to characterize the conduct of the Commonwealth. And this is no mere matter of semantics, for the consequences for the parties may depend very much upon the character to be attributed to that conduct.

The Commonwealth conceded that there had been a promise on its part not to rely upon the Limitation Act. But, it was argued, that could not give rise to a promissory estoppel because the object of promissory estoppel is to avoid detriment, not to secure performance of the promise made. The only possible detriment acknowledged by the Commonwealth to have been suffered by Mr. Verwayen was that involved in preparing the action for trial; such detriment, it was said, could be met by an appropriate order for costs. I return to this aspect later in these reasons.

Any discussion of waiver or estoppel often begins with Craine v. Colonial Mutual Fire Insurance Co. Ltd. [52] , in which Isaacs J. delivered the judgment of the Court. At p. 326, Isaacs J. identified waiver as "an intentional act with knowledge", borrowing the language of Lord Chelmsford L.C. in Earl of Darnley v. Proprietors of London, Chatham, and Dover Railway [53] . Waiver, said his Honour [54] :

looks, however, chiefly to the conduct and position of the person who is said to have waived, in order to see whether he has "approbated" so as to prevent him from "reprobating" - in English terms, whether he has elected to get some advantage to which he would not otherwise have been entitled, so as to deny to him a later election to the contrary. His Honour then contrasted the notion of estoppel by conduct, saying [55] : First of all, the law of estoppel looks chiefly at the situation of the person relying on the estoppel; next, as a consequence of the first, the knowledge of the person sought to be estopped is immaterial; thirdly, as a further consequence, it is not essential that the person sought to be estopped should have acted with any intention to deceive; fourthly, conduct, short of positive acts, is sufficient. 1. (1920) 28 C.L.R. 305. 2. (1867) L.R. 2 H.L. 43, at p. 57. 3. (1920) 28 C.L.R., at p. 326. 4. (1920) 28 C.L.R., at p. 327.

However, the terms are not used consistently and Lord Wright commented in Smyth & Co. v. Bailey & Co. [56] : "The word "waiver" is a vague term used in many senses." See also The "Kanchenjunga" [57] , per Lord Goff of Chieveley. "Estoppel" is likewise susceptible of several meanings. Indeed, in his foreword to Ewart, Waiver Distributed (1917), Roscoe Pound observed, at p. vi:

Having previously looked into the case of that much-enduring word "estoppel" Mr. Ewart now takes up another slippery word worn smooth with overuse and shows us "waiver" as a pseudo-conception. Nevertheless, usage has sanctioned waiver as apt to signify "the legal grounds on which a person is precluded from asserting one legal right when he is entitled to alternative rights inconsistent with each other" and "the legal grounds on which a person is precluded from raising a particular defence to a claim against him": Mason J. in Sargent v. A.S.L. Developments Ltd. [58] . While it has been said that the loss of a right in the circumstances postulated is "better categorised as "election" rather than as "waiver" " (Lord Diplock in Kammins Ballrooms Co. Ltd. v. Zenith Investments (Torquay) Ltd. [59] ), waiver is an appropriate term to describe the loss of a defence otherwise available to a defendant. In that sense it has been said to arise when a defendant "either agrees with the claimant not to raise that particular defence or so conducts himself as to be estopped from raising it" (Lord Diplock (95)) though, again, the terminology is blurred. 1. [1940] 3 All E.R. 60, at p. 70. 2. [1990] 1 Lloyd's Rep. 391, at pp. 397-398. 3. (1974) 131 C.L.R. 634, at p. 655. 4. [1971] A.C. 850, at p. 883.

Waiver, as a notion applicable both to the loss of a right and the loss of a defence, has a respectable lineage. The maxim Quilibet potest renunciare juri pro se introducto (a person may renounce a right introduced for his benefit), referred to in Wilson v. McIntosh [60] , is mentioned by Coke in Beawfage's Case [61] , as "the old rule". In Bovill v. Wood [62] Bayley J. said, in relation to an argument that all contracting parties to an attorney's bill should have been joined in an action for assumpsit, notwithstanding that one had been made bankrupt:

There is no doubt but that the action ought to be brought against Dodgson jointly with the other defendants; he was not discharged absolutely, but only in such way as the Legislature has prescribed; and he was not bound to take the benefit of it, quivis renunciare potest juri pro se introducto. Again, in Bonner v. Wilkinson [63] Abbott C.J. observed: It is certainly true that a party cannot, by his own private instrument, defeat the object of an Act of Parliament, but he may thereby waive a provision intended for his own benefit. 1. [1894] A.C. 129, at p. 133. 2. (1613) 10 Co. Rep. 99b, at p. 101a [77 E.R. 1076, at p. 1080.] 3. (1813) 2 M. & S. 23, at p. 25 [105 E.R. 291, at p. 292]. 4. (1822) 5 B. & Ald. 682, at p. 686 [106 E.R. 1340, at p. 1341].

There is another maxim Omnes licentiam habere his quae pro se indulta sunt renunciare (everyone has liberty to renounce those things which are granted for his benefit) which is also of considerable age: see Rumsey v. North-Eastern Railway Co. [1] . Like most Latin maxims, these two, which are discussed in Broom's Legal Maxims, 10th ed. (1939), pp. 477-478, assert rather than explain. The observation of Windeyer J. in Smith v. Jenkins [2] (though in a different context) holds good:

The intrusion of this Latin maxim into learned commentary, and also into judgments, has caused a confusion which would not have occurred if the writers had condescended to translation and had not taken the maxim into territory where it does not belong. The point of referring to the maxims and to the early decisions is to illustrate the means by which the courts have grappled with the notion to which the label of waiver has been attached and to show that a combination of the two maxims is reflected in the general proposition that a person may waive both a substantive right and an available defence, in the sense that he may agree or choose not to rely upon the one or the other. The maxims embody concepts and that is their value. They are not definitions and, of course, they involve translations. There are translations of the maxims in Jowitt's Dictionary of English Law, 2nd ed. (1977), pp. 1283, 1488. Broom's translation of the second maxim reads: "every man may renounce a benefit or waive a privilege which the law has conferred upon him": p. 478. Nothing in the maxims limits the terms "introduced", "granted" or "conferred" to a benefit arising in some formal way, for example by statute. 1. (1863) 14 C.B. (N.S.) 641, at p. 649 [143 E.R. 596, at p. 600]. 2. (1970) 119 C.L.R. 397, at p. 410.

The idea that waiver involves a renunciation of a right or benefit comes through in the judgment of the Earl of Selborne L.C. in Great Eastern Railway Co. v. Goldsmid [3] . Speaking of a benefit granted to the City of London by a charter of 1st Edward III, his Lordship said:

It [the benefit] is a jus introductum for the particular benefit of the city of London, and it falls within the general principle of law, "Unusquisque potest renunciare juri pro se introducto;" a principle not only of ancient but also of modern application, applicable even where Acts of Parliament have been passed of a much more public character. In such cases, when the rights given have been only private rights, unless there has been also in the Act of Parliament a clause excluding a power of contract, it has been held that by contract or by voluntary renunciation such rights, as far as they are personal rights, may be parted with and renounced. 1. (1884) 9 App. Cas. 927, at pp. 936-937.

At times other expressions have crept into judgments. Thus, in Wright v. John Bagnall & Sons Ltd. [4] , where agreement had been reached between employer and worker that there was a statutory liability on the former to pay compensation for an accident to the latter, the headnote speaks of evidence upon which a judge or arbitrator "may properly find that the employer is estopped from setting up the defence that the request for arbitration was not filed within six months of the accident". Yet the judgment of Collins L.J. [5] , with whom the other members of the Court of Appeal agreed, speaks of the respondent being "debarred" from raising the point that the statutory limitation applied. No member of the Court of Appeal uses the expression "estopped" or indeed "waived". See also Lubovsky v. Snelling [6] .

1. [1900] 2 Q.B. 240. 2. [1900] 2 Q.B., at p. 244. 3. [1944] K.B. 44.

The question is not merely one of terminology; however the law has to work with words. It is important, though, that labels are used with clarity and consistency. It may well be, as suggested in Spencer Bower and Turner, The Law Relating to Estoppel by Representation, 3rd ed. (1977), at p. 318:

Most of the cases which use the term "waiver" (using the term in a sense bringing it within the ambit of this chapter) use it in the sense of "election" as it is used here, and as different on ultimate analysis from estoppel proper. On one view, that is merely to replace one legal label with another. But waiver, seen as a form of election, does have characteristics that distinguish it from estoppel, though there may be occasions when the distinction is not an easy one to draw. The distinction needs further consideration in these reasons. What it is necessary to do is to give to waiver, in any sense relevant for the disposition of this appeal, the aspect that it should properly bear.

Much of the confusion is due to the fact that, as Edward L. Rubin, in a learned article entitled "Toward a General Theory of Waiver", U.C.L.A. Law Review, vol. 28 (1981), observes at p. 478: "Waivers appear in almost every area of law and in connection with almost every type of legal right". Rubin comments, at p. 479: "Precisely the same term with precisely the same effect is used in both criminal and civil law, yet no theory of waiver bridges these two areas." Equally, it may be said, the term is applied to events which occur within the adjudicative process and events which occur prior thereto. In seeking for a definition of waiver, the author points to the difficulties arising from the emphasis in the familiar definition of waiver on "an intentional relinquishment of a known right or privilege": Johnson v. Zerbst [7] . The same emphasis is to be found in Craine [8] . But it has not seemed possible, whether in this country or elsewhere in the common law world, to reconcile the requirement of intention with the notion that waiver may be inferred from conduct. It may be noted that in Craine [9] , Isaacs J. spoke of "intentional" as "such as either expressly or by imputation of law indicates intention ". See also Gresson P. in Auckland Harbour Board v. Kaihe [10] . Because of the difficulty in effecting that reconciliation, it is preferable to speak of waiver in the broad way in which it was referred to by Mason J. in Sargent , though it is still necessary to identify the "legal grounds" on which a person is precluded from asserting a right or from raising a particular defence.

1. (1938) 304 U.S. 458, at p. 464. 2. (1920) 28 C.L.R., at p. 327. 3. (1920) 28 C.L.R., at p. 326. 4. [1962] N.Z.L.R. 68, at p. 88.

Necessarily, questions have to be answered. In what circumstances does waiver operate? In particular, when is a defendant precluded from relying upon a defence such as a plea of limitations? To attempt an answer to the general question first. A defendant may be precluded from asserting a right or from raising a defence, as a matter of contract. In Tropical Traders Ltd. v. Goonan [11] , where this Court was considering the consequences of repeated acquiescence by one party to a contract in non-observances by the other party of stipulations as to time, Kitto J. commented [12] , that "it may not matter whether the result is described as a promissory estoppel or a waiver or a variation of the contract by mutual, though tacit, consent". Yet, variation of contract does stand in a category of its own since, as the law presently stands, consideration is necessary to support the altered bargain. In many cases where waiver is sought to be argued, consideration is not present; the situation may be an entirely non-contractual one, as in Vakauta v. Kelly [13] , where the question was whether a party to litigation, with knowledge of the right to take objection on the ground of bias on the part of the trial judge, lost that right through failure to take objection at the appropriate time.

1. (1964) 111 C.L.R. 41. 2. (1964) 111 C.L.R., at p. 52. 3. (1989) 167 C.L.R. 568.

There may be much to be said for the suggestion made by Wootten J. in Wilson v. Kingsgate Mining Industries Pty. Ltd. [14] , and noted in Cheshire and Fifoot's Law of Contract, 5th Aust. ed. (1988), pp. 628-629, "that the time is at hand when these various approaches to the same or similar problems should be rationalized under one subsuming principle". The learned authors offer, as a subsuming principle, the statement by Dixon J. in Thompson v. Palmer [15] (though said in regard to estoppel in pais), that the law will not allow "an unjust departure by one person from an assumption adopted by another which would operate to that other's detriment".

1. [1973] 2 N.S.W.L.R. 713, at p. 730. 2. (1933) 49 C.L.R. 507, at p. 547.

Whether or not the time is ripe for a subsuming principle, the shape that this case has taken since its inception makes the formulation here of such a principle inappropriate. More importantly, such a formulation has sweeping implications, not only for waiver and estoppel, but for other areas of the law as well, not least the doctrine of consideration. In the circumstances of the present case, the efficacy of the Commonwealth's limitations defence must fall to be determined within the language of waiver or estoppel.

In my view, waiver, by that name, has a role to play. And it is a role which involves no confusion with variation of contract or promissory estoppel. It may be seen as a form of election between inconsistent rights, in the former of the categories mentioned by Mason J. in Sargent [16] . Election implies that a choice must be made between two rights which are mutually exclusive. "Obviously there can be no election, choosing one course to the exclusion of another, when in fact there is only one course to take, or where the two courses are such that the adoption of one of them does not necessarily indicate a final intention to abandon the other": Spencer Bower and Turner, p. 342. But, in the second of those categories, "the legal grounds on which a person is precluded from raising a particular defence ", an election is involved, only in the sense that a defendant may choose to take a jurisdictional point, rely upon an irregularity in the proceedings, plead a particular defence, or take some other step in the adjudicative process, or he may choose not to do so. But he may not take up "two inconsistent positions", the language used in Craine [17] . It may be, therefore, that "election" is best reserved for the former of Mason J.'s categories and "waiver" for the latter. The distinction is noted by Lord Wright in Smyth & Co. v. Bailey & Co. [18] .

1. (1974) 131 C.L.R., at p. 655. 2. (1920) 28 C.L.R., at p. 326. 3. [1940] 3 All E.R., at p. 70.

Halsbury's Laws of England, 4th ed. (1976), vol. 16, par. 1471, part of which reflects the judgment of Lord Hailsham of St Marylebone L.C. in Banning v. Wright [19] , offers the following definition which comes close to this notion; nevertheless, it is open to the objection that it tends to blur different concepts:

Waiver is the abandonment of a right in such a way that the other party is entitled to plead the abandonment by way of confession and avoidance if the right is thereafter asserted, and is either express or implied from conduct. It may sometimes resemble a form of election, and sometimes be based on ordinary principles of estoppel, although, unlike estoppel, waiver must always be an intentional act with knowledge. 1. [1972] 1 W.L.R. 972, at p. 979; [1972] 2 All E.R. 987, at p. 998.

In this appeal we are concerned with waiver as it exists within the adjudicative process. It is commonplace to speak of a person "waiving" a right, for instance, by submitting to the jurisdiction of a court which otherwise has no jurisdiction over him, by not insisting upon arbitration, where an agreement so provides, by not taking advantage of some irregularity in proceedings or by not pressing a particular argument that is available at trial: see, by way of example, Graham v. Ingleby [20] ;Park Gate Iron Co. v. Coates [21] ; Ward v. Raw [22] ; Fry v. Moore [23] ; Shrager v. Basil Dighton Ltd. [24] ; Water Board v. Moustakas [25] .

1. (1848) 1 Ex. 651 [154 E.R. 277]. 2. (1870) L.R. 5 C.P. 634. 3. (1872) L.R. 15 Eq. 83. 4. (1889) 23 Q.B.D. 395. 5. [1924] 1 K.B. 274. 6. (1988) 62 A.L.J.R. 209; 77 A.L.R. 193.

Waiver, in the sense used for the purposes of this appeal, may be found in the deliberate act of a defendant not to rely upon a defence available to him. That is not to say that there must be an intention to bring about the consequences of waiver; rather, the conduct from which waiver may be inferred, must be deliberate. Detriment is not an essential attribute of waiver, though it will often be found as a consequence. Within the adjudicative process at any rate, it is enough that the defendant "renounces" a defence which is available to him and which is there for his benefit.

A defence available to a defendant, whether it be on the facts or on the law, is not waived merely because the defendant does not initially plead that defence. It is commonplace for pleadings to change as an action progresses, whether by way of expansion or contraction (though usually the former). But what happened in the present case is more fundamental than a pleading point. The situation is not simply that the Commonwealth had filed a defence to the action and later sought to add a plea of limitation to that defence. The Commonwealth sought to adopt a position which had been open to it at the outset but which it deliberately chose not to make a part of the issues for adjudication. The stance of the Commonwealth from the beginning, consistent with its communications to Mr. Verwayen's advisers, was that it was not relying upon the Limitation Act, indeed that it was not defending the action, save as to the amount of damages to be awarded to Mr. Verwayen. It was on that footing that the plaintiff pursued his action for damages right through to the listing of the action for the assessment of damages. To uphold a limitations plea in those circumstances would be to permit the Commonwealth to rely upon a defence which it had unequivocally renounced.

Section 5(6) of the Limitation Act provides that no action for damages for negligence in respect of personal injuries "shall be brought after the expiration of three years after the cause of action accrued". Such a provision has been long held to go, not to the jurisdiction of a court to entertain a claim, but to the remedy available and hence to the defences which may be pleaded. Absent a plea of limitations, in those circumstances the matter does not arise for the consideration of the court: see Ronex Properties Ltd. v. John Laing Construction Ltd. [26] and the authorities there cited. Equally, it is well established that a provision such as s. 5(6) is procedural in nature: Ketteman v. Hansel Properties [27] ; see also Admiralty Commissioners v. Valverda (Owners) [28] . Such a right is capable of being waived if it is for the benefit of the party concerned: Phillips v. Martin [29] ; Wilson v. McIntosh [30] ; Brown v. The Queen [31] . The Commonwealth renounced and thereby waived its right to rely upon the defence of limitations, a defence which was otherwise available to it and which was for its benefit.

1. [1983] Q.B. 398. 2. [1987] A.C., at p. 219. 3. [1938] A.C. 173, at p. 185. 4. (1890) 11 N.S.W.L.R. 153. 5. [1894] A.C. 129. 6. (1986) 160 C.L.R. 171, at p. 178.

The passage from Halsbury , referred to earlier in these reasons, concludes:

The waiver may be terminated by reasonable but not necessarily formal notice unless the party who benefits by the waiver cannot resume his position, or termination would cause injustice to him.

Waiver, in the sense relevant for the purposes of this appeal, is not capable of being withdrawn. It is of the essence of waiver in this sense that the defendant has unequivocally renounced his right to rely upon the particular defence; once the defence has been so renounced (and this will be hard to establish except in a case as clear as this one), the defendant should not be permitted to rely upon it. In this context, to say that waiver may be terminated unless the other party cannot resume his position is, once again, to move into the area of estoppel. This is made evident by the authority cited by Halsbury in support of the proposition - Ajayi v. R.T. Briscoe (Nigeria) Ltd. [32] speaks expressly of promissory estoppel. As to the causing of injustice to the other party, the authority cited is W.J. Alan & Co. v. El Nasr Export & Import Co. [33] . That case concerned contracts for the sale of coffee and a question as to the currency in which payment should be made. Lord Denning M.R. spoke of waiver, but in relation to the enforcement of rights under a contract, adding [34] :

It may be too late to withdraw: or it cannot be done without injustice to the other party. In that event he is bound by his waiver. He will not be allowed to revert to his strict legal rights. This is waiver in the first of the two senses mentioned by Mason J. in Sargent . It is the second of those senses with which this appeal is concerned. It follows that I disagree with the view expressed in Kerrison v. Martin & Heyward [35] , that "any such unilateral waiver without consideration can be terminated at any time", at least if it is thought to apply to waiver as I have sought to identify it in the present case. Because waiver, in this sense, involves unequivocal renunciation or abandonment of a defence, it may occur at any stage of the adjudicative process. In the ordinary course, proof that there has been such a renunciation or abandonment will be the harder to establish, the earlier the stage reached in that process. But that is an evidentiary problem; it does not mean that a particular stage in the adjudication process must be reached before waiver of a defence may occur. 1. [1964] 1 W.L.R. 1326; [1964] 3 All E.R. 556. 2. [1972] 2 Q.B. 189. 3. [1972] 2 Q.B., at p. 213. 4. [1975] V.R. 401, at p. 405.

What I have said regarding the limitations plea applies equally to the defence that the Commonwealth was engaged in combat exercises. There is no statutory provision involved but, in the sense in which waiver is used in these reasons, the Commonwealth had available to it, by way of answer to Mr. Verwayen's claim, a contention that it owed no duty of care to him in the circumstances. The distinction drawn by Windeyer J. in Australian Iron & Steel Ltd. v. Hoogland [36] , between "a condition of the remedy rather than an element in the right" was drawn in the context of a limitations defence and is not necessarily apposite in all situations in which waiver arises. For the reasons already given, the Commonwealth must be taken to have renounced its right to rely upon a defence that, in the circumstances of this case, it owed no duty of care to Mr. Verwayen. There is no operative difference between this defence and the limitations plea. In one case the Commonwealth said to Mr. Verwayen: "There is available to us an argument that, in the circumstances prevailing at the time you were injured, we owed you no duty of care. But we abandon any such argument." In the other case the Commonwealth said: "There is available to us an argument that any claim you might otherwise have is statute barred. But we abandon any such argument." To abandon the combat exercise defence offended no statutory provision, whether for the benefit of the public or otherwise, and no rule of public policy. In all the circumstances the Commonwealth must be held to have renounced that particular answer to Mr. Verwayen's claim.

The conclusions I have reached make it unnecessary to deal with the argument based on estoppel. But on the present state of the authorities, the consequence of any promissory estoppel is that the court should enforce the promise only as a means of avoiding detriment and to the extent necessary to achieve that end: see Waltons Stores (Interstate) Ltd. v. Maher [1] . In Mr. Verwayen's case, that end may be achieved by compensating him for what he has lost by way of costs in pursuing the action. If there are other factors to be taken into account (and before O'Bryan J. counsel for the respondent contended that there were such factors), they have not been established in the proceedings that have taken place. Whether Mr. Verwayen should now be given the opportunity to supplement the material relevant to detriment is a matter I need not pursue for he has succeeded in making good his claim of waiver.

Something must be said, however, about the consequences of these conclusions for this appeal, having regard to the present state of the pleadings. By its amended defence the Commonwealth denied negligence and pleaded s. 5(6) of the Limitation Act and that, by reason of combat exercises in which the Voyager and the Melbourne were engaged at the relevant time, no duty of care was owed to Mr. Verwayen. The reply to that defence asserted, inter alia, that the Commonwealth had waived or was estopped from raising the limitations defence and the combat exercise defence. The reply did not assert that the Commonwealth had waived or was estopped from raising its general denial of negligence. Those pleadings stand though possible consequences were raised by this Court during the hearing of the appeal. A conclusion that the Commonwealth waived the limitations defence and the combat exercise defence does not directly touch the general denial of negligence.

Having regard to the issues raised by the appeal, it is appropriate that the appeal be dismissed. It may well be that the Commonwealth will agree to the action proceeding to trial for the assessment of damages only, since the combat exercise defence was the only basis upon which the absence of a duty of care was sought to be raised and, once that issue has been removed from the action, negligence may no longer be contested. But that is a matter to which Mr. Verwayen's advisers must direct their attention and, if necessary, seek an amendment to the reply to assert that the Commonwealth is precluded from denying negligence. In all the circumstances, it is hard to see any basis on which such an application may be refused. Although the denial of negligence presently remains in the defence, the effect of this judgment is that the Commonwealth is held to its admission of liability. The only matter on which the Commonwealth should now be heard is as to the amount of damages to which Mr. Verwayen is entitled.

In February 1964 there was a collision at sea between two ships of the Royal Australian Navy, H.M.A.S. Voyager and H.M.A.S. Melbourne. Many of the crew of the Voyager were injured, some fatally. Mr. Verwayen was on board the Voyager and claims to have suffered injuries in the collision.

It seems that for a number of years it was generally assumed that there was no liability in negligence on the part of the Commonwealth of Australia, its officers, servants or agents in respect of the collision. However, following the decision of this Court in Groves v. The Commonwealth [2] , the services of Messrs Vaccaro and Taylor, barristers and solicitors of Myrtleford, Victoria, were retained by some of the survivors from the Voyager to investigate the possibility of their recovering damages from the Commonwealth. In November 1983 Messrs Vaccaro and Taylor secured agreement from the Commonwealth that it would "not rely on the Statute of Limitations" in an action arising out of the collision commenced by Mr. Robert Palmer. In February 1984 the Commonwealth admitted liability in that action. Damages were to be assessed.

In September 1984 Messrs Vaccaro and Taylor wrote to the Secretary, Department of Defence, noting that in the case of Mr. Robert Palmer the Commonwealth had "waived the Statute of Limitations" and had "admitted liability". A request was made on behalf of Mr. Verwayen and four other persons that "you treat these men the same and waive the Statute to allow us to proceed on their behalf". A reply was received from the Minister Assisting the Minister for Defence stating that the request had been referred to the Australian Government Solicitor (Victoria) who would advise of the Commonwealth's position.

On 2 November 1984, Mr. Verwayen commenced proceedings against the Commonwealth in the Supreme Court of Victoria claiming damages for negligence. On 25 January 1985, the Australian Government Solicitor advised that the Commonwealth proposed to admit liability and to waive the Statute of Limitations in that action. Thereafter, on 14 March 1985, the Australian Government Solicitor delivered a defence which, in terms, admitted negligence as pleaded in Mr. Verwayen's statement of claim. There was no plea that the action was statute barred. As the pleadings then stood, the only issue was as to Mr. Verwayen's injuries, loss and damages. Thereafter, during 1985, the Australian Government Solicitor joined in five applications made by or on behalf of Mr. Verwayen for an expedited hearing of that issue. In November 1985, the Minister Assisting the Minister for Defence wrote to Mr. Verwayen stating, inter alia, that "the Commonwealth has admitted negligence and is not pressing the statutory limitation period as a defence". In that letter there was an expression of regret as to "any delay in the finalization of claims" and an assurance that "all reasonable steps are being taken to expedite these matters, consistent with normal legal requirements".

Mr. Verwayen's action was prepared for trial. It seems that it was expected that the trial would be held during the Wangaratta sittings commencing on 3 June 1986. However, on 22 May 1986, application was made for leave to amend the Commonwealth's defence. The application was opposed. Leave was granted. An amended defence was filed on 29 May 1986. By that amended defence the Commonwealth denied negligence and asserted that the Voyager and the Melbourne were, at the relevant time, warships engaged in combat exercises and that, by reason thereof, no duty of care was owed to Mr. Verwayen. For the sake of convenience the matter thus pleaded will be referred to as "the combat exercise defence". Additionally, it was pleaded that the action was barred by s. 5 of the Limitation of Actions Act 1958 Vict..

A reply to the amended defence was filed. Issue was joined on the denial of negligence. Additionally, the reply -

(a) denied that the Voyager and the Melbourne were engaged in combat exercises;

(b) asserted that the claim that the Voyager and the Melbourne were warships engaged in combat exercises did not amount, in law, to a defence to the plaintiff's claim;

(c) asserted that "the Limitation Act does not apply to [the Commonwealth]";

(d) alternatively, asserted that the Commonwealth had waived or was estopped from raising "the combat exercise defence" and the defence that the action was statute barred.

The question raised by the plea that "the Limitation Act does not apply to [the Commonwealth]" has been decided against Mr. Verwayen and that decision has not been challenged. It is convenient to note two other matters relating to the amended defence and the reply. First, the reply did not assert that the Commonwealth had waived any right to raise or was estopped from raising a general denial of negligence. This may have resulted from an assumption, which seemed to underlie the argument put to this Court, that the only basis on which negligence is denied by the Commonwealth is that comprehended in "the combat exercise defence". Secondly, the questions of waiver and estoppel raised on behalf of Mr. Verwayen go to both "the combat exercise defence" and the defence that the action is statute barred.

The issues raised by the amended defence and the reply were determined as preliminary issues by O'Bryan J., his Honour taking the view that none of these issues involved any factual issue for a jury to determine. So far as is presently relevant, his Honour held (i) that "the combat exercise defence" did not amount, in law, to a defence to the plaintiff's action; and (ii) that the Commonwealth was not precluded (whether by waiver or estoppel) from relying on a defence that the action was statute barred. In the result, judgment was entered for the Commonwealth, but, by reason of the course which the action had taken, the Commonwealth was ordered to pay Mr. Verwayen's costs of and incidental to the hearing before O'Bryan J.

Mr. Verwayen appealed and the Commonwealth cross-appealed to the Full Court of the Supreme Court of Victoria. It was held by majority (Kaye and Marks JJ., King J. dissenting) that the Commonwealth was estopped, by virtue of a promissory estoppel, from relying on its defence that the action was statute barred. It was further held by the majority (King J. not finding it necessary to decide the issue raised by "the combat exercise defence") that the facts did not disclose that "at the time of collision Voyager was engaged in a military manoeuvre as such or otherwise doing anything which could remotely be described as training for battle". Accordingly, the appeal was allowed and the cross-appeal was dismissed. It was ordered that the judgment entered at first instance be set aside and that the proceedings be remitted for trial on the issues of negligence and damages. The order remitting the issue of negligence flowed from the denial of negligence by the Commonwealth in its amended defence, which denial was not the subject of any claim of waiver or estoppel in the reply. The Commonwealth now appeals to this Court.

In this Court two distinct issues were argued on behalf of the Commonwealth. First, it was argued that the Commonwealth was not precluded from raising the defence that the action was statute barred (appeal ground 4). Secondly, it was argued that "[t]he Full Court erred in failing to find that [Mr. Verwayen] was owed no duty of care by [the Commonwealth] or by any member of the armed forces engaged in the operations of either or both of H.M.A.S. Melbourne and H.M.A.S. Voyager " (appeal ground 5).

It is not now in issue that if the Commonwealth is entitled to rely on its defence that Mr. Verwayen's action is statute barred, it is a complete answer to his claim. Accordingly, if the Commonwealth is correct in its first argument, it is unnecessary to consider its second argument. And, because the questions of waiver and estoppel go equally to "the combat exercise defence" and the defence that the action is statute barred, then, unless there is some difference arising from the nature of the two defences, if the Commonwealth is not successful on its first argument, the question posed by "the combat exercise defence" does not arise.

The starting point of the argument made on behalf of the Commonwealth is that waiver, unless constituted by deed or by an agreement supported by consideration, does not exist independently of estoppel. There was neither a deed nor agreement supported by consideration in the present case. The Commonwealth acknowledges that there was a promise, knowingly and intentionally made, which gave rise to a promissory estoppel. But, it was argued, the object of promissory estoppel is to avoid detriment, not to secure performance of the promise made. The only detriment suffered by Mr. Verwayen, it was said, was that involved in preparing his action for hearing. And, according to the argument, that detriment was fully and appropriately avoided by cost orders fashioned to the particular circumstances of the case.

In Craine v. Colonial Mutual Fire Insurance Co. Ltd. [3] this Court, in a judgment delivered by Isaacs J., sought to distinguish between waiver and estoppel by conduct; it was said that "estoppel may be established where waiver cannot, and conversely waiver may be found where estoppel does not exist" [4] . The distinction made was between "an intentional act with knowledge" (Earl of Darnley v. Proprietors of London, Chatham, and Dover Railway [5] ) and conduct which, even if done unintentionally, without knowledge and not amounting to a positive act, is such that "it would be unjust to throw the consequences on the person who believed his statement and acted on it": Sarat Chunder Dey v. Gopal Chunder Laha [6] .

1. (1920) 28 C.L.R. 305, at pp. 326-328. 2. (1920) 28 C.L.R., at p. 328. 3. (1867) L.R. 2 H.L. 43, at p. 57. 4. (1892) L.R. 19 Ind. App. 203, at p. 216.

Contemporary understanding of the nature of the conduct which will ground an estoppel allows that the conduct which was identified in Craine as a waiver is conduct which may ground an estoppel. See, e.g., Thompson v. Palmer [7] , per Dixon J., and Grundt v. Great Boulder Pty. Gold Mines Ltd. [8] , per Dixon J. And that the same conduct might be characterized either as waiver or as founding an estoppel was recognized by Isaacs J. in Sandringham Corporation v. Rayment [9] .

1. (1933) 49 C.L.R. 507, at p. 547. 2. (1937) 59 C.L.R. 641, at p. 675. 3. (1928) 40 C.L.R. 510, at pp. 528-529.

Given that the same conduct may constitute what was characterized as waiver in Craine and provide the foundation for an estoppel, there has been a tendency, in recent times, to question whether and, if so, in what circumstances waiver exists independently of the general law of estoppel. And this question has led to the further question whether the word "waiver" is not productive of confusion. Thus in Kammins Ballrooms Co. Ltd. v. Zenith Investments (Torquay) Ltd. [10] , Lord Diplock observed that the word "waiver" was "sometimes used loosely to describe a number of different legal grounds on which a person may be debarred from asserting a substantive right or from raising a particular defence". His Lordship went on to say that the first type was "better categorised as "election" rather than as "waiver" " and that "[t]he ordinary principles of estoppel apply to [the second category of waiver]". In the same case Viscount Dilhorne [11] quoted the statement in Spencer Bower and Turner, The Law Relating to Estoppel by Representation, 2nd ed. (1966), pp. 291-292, that the word "waiver" has "dangers which may be avoided only by forgoing it as a useful term when considering either estoppel or election" and that its use in the authorities is more probably to "be found to connote "election" than "estoppel" ". (See now 3rd ed. (1977), pp. 319-320.)

1. [1971] A.C. 850, at p. 882. 2. [1971] A.C., at pp. 872-873.

In Craine [12] , Isaacs J. referred to waiver as "a doctrine of some arbitrariness introduced by the law to prevent a [person] in certain circumstances from taking up two inconsistent positions". The expression "taking up two inconsistent positions" is wider than the expression "asserting two inconsistent rights". It is the assertion of inconsistent rights that is generally understood to be at the heart of what is called "election". See Sargent v. A.S.L. Developments Ltd. [13] , per Stephen J.; Lissenden v. C.A.V. Bosch Ltd. [14] , per Lord Wright. For present purposes the question whether there is a doctrine, be it called "waiver" or anything else, which operates by reference to the taking of inconsistent positions rather than the assertion of inconsistent rights can be confined to the situation where, in the course of litigation, a person asserts a right to take a position which is inconsistent with one earlier taken in the same litigation.

1. (1920) 28 C.L.R., at p. 326. 2. (1974) 131 C.L.R. 634, at p. 641. 3. [1940] A.C. 412, at pp. 435-436.

If, in the course of litigation, a person fails to plead a matter, take an available objection or pursue a particular point of law, the matter proceeds on the basis that the point which might have been taken is not in issue. Were it otherwise the conduct of litigation would be unmanageable. Of course, leave may be granted for the point to be raised notwithstanding the failure to take the point at the appropriate time. Generally, leave is granted if the point can be raised without injustice to the other party. That question may depend upon whether disadvantage to the other party can be avoided by adjournment or an appropriate costs order. But other issues may be taken into account. In Ketteman v. Hansel Properties Ltd. [15] Lord Griffiths said "justice cannot always be measured in terms of money". His Lordship then observed that there was to be weighed in the balance "the strain the litigation imposes on litigants , the anxieties occasioned by facing new issues, the raising of false hopes". Additionally, his Lordship noted the necessity to take into account "the pressure on the courts" and the public interest in "legal business [being] conducted efficiently".

When a party to litigation deliberately chooses not to take a point or fails to take a point when it comes to notice, the courts may adopt a more stringent attitude, treating the point as having been irrevocably abandoned. Usually the party who has thus failed to take the point is said to have "waived" it.

In Wilson v. McIntosh [16] a question arose as to the consequence to be attached when a party to litigation had stated his case and required the other party to file her case in an application for the removal of a caveat under the Real Property Act 1862 N.S.W. (26 Vict. No. 9) notwithstanding that the caveat had by then lapsed. In that case the Privy Council approved a statement of Sir Frederick Darley C.J. in Phillips v. Martin [17] , where it was said:

[I]t is quite clear that a man may by his conduct waive a provision of an Act of Parliament intended for his benefit. The caveator was not brought into Court in any way until the caveat had lapsed. And now the applicant, after all these proceedings have been taken by him, after, doubtless, much expense has been incurred on the part of the caveator, and after lying by and hoping to get a judgment of the Court in his favour - asks the Court to do that which but for some reasons known to himself he might have asked the Court to do before any other step in the proceedings had been taken. I think he is altogether too late. It is to my mind a clear principle of equity, and I have no doubt there are abundant authorities on the point, that equity will interfere to prevent the machinery of an Act of Parliament being used by a person to defeat equities which he has himself raised, and to get rid of a waiver created by his own acts. The same principle is to be found in Graham v. Ingleby [18] ; Park Gate Iron Co. v. Coates [19] ; and St Victor v. Devereux [20] . 1. [1894] A.C. 129. 2. (1890) 11 N.S.W.L.R. 153, at p. 158. 3. (1848) 1 Ex. 651 [154 E.R. 277]. 4. (1870) L.R. 5 C.P. 634. 5. (1845) 14 L.J. Ch. 244.

There are two matters of significance in the statement approved in Wilson v. McIntosh that serve to indicate that what was considered in that case and in the case of Phillips v. Martin was neither election nor estoppel as those doctrines are presently understood. First, the situation there considered concerned the taking of inconsistent positions rather than the assertion of inconsistent rights in the strict sense. Secondly, to the extent that the incurring of expense might equate with detriment for the purposes of the law of estoppel, that detriment was presumed rather than established. One other matter may also be noted by reference to Wilson v. McIntosh. If the incurring of expense were the only consideration, it is difficult to see that it could not have been dealt with by an order for costs. But it was not the only or, indeed, the relevant consideration. The relevant consideration was that there were "equities which he [had] himself raised". What those equities were was not made explicit.

To some extent the equity which underlies the doctrine approved and applied in Wilson v. McIntosh can be distilled from the situations in which the doctrine has been applied or, if not applied in terms, like considerations have resulted in a party to litigation being precluded from taking a point previously open.

A party to litigation who has failed to object that a condition attaching to the exercise of jurisdiction has not been satisfied or that the proceedings were irregularly instituted may, by reason of his subsequent participation in the proceedings, be precluded from later raising the defect. See, e.g., Broad v. Perkins [21] ; In re Jones v. James [22] ; Moore v. Gamgee [23] . So too, a litigant may be precluded from raising a matter going to the disqualification of the person constituting the court if, with knowledge of the disqualification, he participates in the proceedings without objection. See Vakauta v. Kelly [24] . See also Corrigal v. London and Blackwall Railway Co. [25] ; Shrager v. Basil Dighton Ltd. [26] , a case concerning jurisdiction of Official Referees appointed under the Rules of the Supreme Court (U.K.).

1. (1888) 21 Q.B.D. 533. 2. (1850) 19 L.J. Q.B. 257. 3. (1890) 25 Q.B.D. 244. 4. (1989) 167 C.L.R. 568. 5. (1843) 5 Man. & G. 219 [134 E.R. 545]. 6. [1924] 1 K.B. 274.

Once a matter has passed into judgment similar considerations may operate to limit the matters which may be raised on appeal. A party to an appeal may be precluded from taking a point not argued at trial, even if the matter was pleaded and particularized: Water Board v. Moustakas [27] . See also Suttor v. Gundowda Pty. Ltd. [28] ; Maloney v. Commissioner for Railways (N.S.W.) [29] . So too, a party to an appeal may be precluded from relying on the pleadings if some different basis was chosen by the parties for the determination of the matter at trial. See Browne v. Dunn [30] , cited with approval in Rowe v. Australian United Steam Navigation Co. Ltd. [31] ; Gould and Birbeck and Bacon v. Mount Oxide Mines Ltd. (In liq.) [32] , per Isaacs and Rich JJ.

1. (1988) 62 A.L.J.R. 209; 77 A.L.R. 193. 2. (1950) 81 C.L.R. 418. 3. (1978) 52 A.L.J.R. 292; 18 A.L.R. 147. 4. (1893) 6 R. 67, at pp. 75-76. 5. (1909) 9 C.L.R. 1, at pp. 24-25. 6. (1916) 22 C.L.R. 490, at p. 517.

There is a common aspect to the situations above discussed. The relationship of the parties has changed. In cases involving questions relating to jurisdictional defect or irregularity attending the institution of the proceedings the parties have become or are treated as having become parties to a proceeding. In the case of failure to raise a matter of personal disqualification, the parties have entered a new relationship, namely parties to a proceeding which is in the course of adjudication. Again, once a matter has passed into judgment, the relationship of the parties is according to the judgment, subject only to such powers as may be exercised by an appellate court if an appeal is instituted. And, it is significant that a respondent to an appeal who fails to object that the appeal has not been properly instituted may be precluded from later raising that issue. See Park Gate Iron Co.; Ward v. Raw [33] . Again, in that situation the parties are or are deemed to be in a new relationship, namely, that of appellant and respondent.

Perhaps there is a principle of wider application, but it is clear that a party to litigation will be held to a position previously taken (that position having been intentionally taken with knowledge) if, as a result of that earlier position, the relationship of the parties has changed. The changed relationship, in the terms used in Phillips v. Martin and approved in Wilson v. McIntosh, constitutes an "equit[y] which [the other] has raised".

Given that the position deliberately adopted by one party has brought about a change in the relationship of the litigants, a doctrine which holds the parties to that relationship may be seen as resting either on general policy considerations or on principles analogous to those of estoppel. Such a doctrine, by ensuring fair dealing in the conduct of litigation and by promoting the finality of litigation, aids the efficient administration of justice. By analogy with the general law of estoppel, one may treat the doctrine as operating by reference to an assumption that a particular relationship has been constituted, which assumption has been occasioned by the deliberate failure to take an available point when it comes to notice. But the doctrine does not require proof that detriment will be suffered. Rather, to continue the analogy, it presumes that putting the parties back in some earlier relationship is, itself, a detriment. And, in a sense, so it is, for there could be no certainty that the parties would thereafter secure the rights against each other that marked the relationship brought about by the failure to take an available point. For example, if proceedings had to be started afresh because of some procedural defect attending their institution, there could be no certainty that service would again be effected or that it would be effected before the expiry of some limitation period. Although the doctrine is analogous to general principles of estoppel, it operates because there is no injustice in holding a party to a changed relationship where that relationship is referable to a deliberate failure to take an available point. Conversely, if the failure is not deliberate, there is no injustice (whether viewed from the perspective of estoppel or otherwise) in allowing that point to be later taken if disadvantage to the other side can be avoided by adjournment or an order as to costs. It matters not whether the doctrine is called "waiver" or anything else. For ease of expression I shall continue to use the word "waiver", using it in the present context to signify deliberate action or inaction which has resulted in a changed relationship to which the parties will be held whether or not detriment is actually established.

Ordinarily the failure to raise a particular defence will not effect a change in the relationship of parties to litigation. If, for example, liability is in contest, the relationship is not altered by expanding the grounds of that contest. Thus, ordinarily and subject to those considerations relevant to the grant of leave, the pleadings may be amended to enable all matters relevant to that issue to be raised. See, e.g., Cropper v. Smith [34] . However, in the present case, the relationship of the parties was altered by the defence originally delivered by the Commonwealth. As earlier mentioned that defence, in terms, admitted negligence. That admission having been made and it not having been pleaded that the action was statute barred, the relationship between Mr. Verwayen and the Commonwealth changed to one in which Mr. Verwayen became entitled to a verdict in his favour, subject only to damages being established and assessed. This new entitlement was recognized by the Commonwealth when, on five occasions, it joined in applications for an expedited hearing on the issue of damages. The new relationship was the direct result of the Commonwealth's original defence. And, it is not in issue that the Commonwealth intentionally and with knowledge of the defences available to it delivered a defence admitting liability and raising neither "the combat exercise defence" nor a defence that the action was statute barred. Unless something renders "the combat exercise defence" or the defence that the action was statute barred insusceptible of abandonment, Mr. Verwayen is entitled to have his claim determined without intrusion of the issues thereby raised.

The starting point of any consideration of whether the defences are insusceptible of abandonment must be s. 64 of the Judiciary Act 1903 Cth which relevantly provides:

In any suit to which the Commonwealth is a party, the rights of parties shall as nearly as possible be the same as in a suit between subject and subject. It was not contended that anything requires that the present matter be determined on any different basis from that applicable in proceedings between subject and subject.

The general principle is that "an individual cannot waive a matter in which the public have an interest": Graham v. Ingleby [35] , per Alderson B. referring to Reg. v. Bloxham [36] . See also Ross v. Australian Postal Commission [37] ; Phillips v. Martin [38] . Conversely, a person may waive a right that is for his or her own benefit: Great Eastern Railway Co. v. Goldsmid [39] ; Toronto Corporation v. Russell [40] . Where a right is conferred by statute a question may arise whether the statute confers a personal or a public right. See, for example, Ross [41] ; Park Gate Iron Co. [42] . A statutory right to plead that an action is statute barred, such as that conferred by s. 5 of the Limitation of Actions Act, which bars the remedy rather than the right or the right to invoke a court's jurisdiction, is a personal right. See Kammins [43] , per Lord Diplock. Cf. Adams v. Chas. S. Watson Pty. Ltd. [44] , where the issue under consideration was whether a time limitation ousted jurisdiction.

1. (1848) 1 Ex., at p. 657 [154 E.R., at p. 279]. 2. (1844) 6 Q.B. 528 [115 E.R. 197]. 3. (1982) 69 F.L.R. 376, at p. 382. 4. (1890) 11 N.S.W.L.R., at p. 158. 5. (1884) 9 App. Cas. 927, at pp. 936-937. 6. [1908] A.C. 493, at p. 500. 7. (1982) 69 F.L.R., at pp. 382-383. 8. (1870) L.R. 5 C.P., at pp. 638-639. 9. [1971] A.C., at p. 881. 10. (1938) 60 C.L.R. 545.

From one perspective "the combat exercise defence" asserts a defence deriving from what may be described as an inherently governmental function. However, on proper analysis, the matter thus pleaded does no more than assert that, in the particular circumstances, no duty of care was owed to Mr. Verwayen. The right to answer a claim of negligence by the denial of a duty of care is a personal right. Accordingly, both "the combat exercise defence" and the defence that Mr. Verwayen's action was statute barred were susceptible of waiver. And being so susceptible, for the reasons earlier given, the Commonwealth is precluded from relying on them.

It follows from what has been said that, had Mr. Verwayen's reply asserted that the Commonwealth was precluded from denying negligence, Mr. Verwayen would be entitled to have his claim determined in a hearing limited to the issue of damages. It may be that an application will be made for leave to amend the reply. Unless such application is made and granted, Mr. Verwayen's claim must proceed to a hearing on the issues of negligence and damages as ordered by the Full Court.

Although it is not necessary for me to deal with the argument that the object of an estoppel is to avoid detriment and not to make good the assumption on which it is founded, it is convenient that I note my agreement with Mason C.J. that the substantive doctrine of estoppel permits a court to do what is required to avoid detriment and does not, in every case, require the making good of the assumption. Even so, it may be that an assumption should be made good unless it is clear that no detriment will be suffered other than that which can be compensated by some other remedy. Where the nature or likely extent of the detriment cannot be accurately or adequately predicted it may be necessary in the interests of justice that the assumption be made good to avoid the possibility of detriment even though the detriment cannot be said to be inevitable or more probable than not. On that basis and were the present matter to be determined by reference to the substantive doctrine of estoppel, the mere possibility of increased stress and anxiety to Mr. Verwayen would tend in favour of making good the assumption that liability would not be put in issue by the Commonwealth. As that aspect was not fully explored in argument it is undesirable that I express a concluded view on the matter. However, that aspect aside, the present matter was determined, on the application of the Commonwealth and contrary to the argument made on behalf of Mr. Verwayen, on the basis that the issues raised by the pleadings involved no issue of fact for a jury to determine. Were the resolution of this case to depend on whether or not Mr. Verwayen could establish detriment over and above that which is appropriately dealt with by an order for costs it would be necessary, at the very least, that he be given an opportunity of making that case.

The Commonwealth of Australia appeals against an order that an action brought against it by Bernard Leonardus Verwayen ("the plaintiff") be remitted for trial by jury on the issues of negligence and damages. The order, made by the Full Court of the Supreme Court of Victoria (Kaye and Marks JJ., King J. dissenting), set aside a judgment made by O'Bryan J. in favour of the Commonwealth. His Honour had entered judgment for the Commonwealth upon the ground that the plaintiff's action was barred by s. 5 of the Limitation of Actions Act 1958 Vict. ("the Limitation Act"). The issue in the appeal is whether the Commonwealth waived its right to rely on the Limitation Act and its right to rely on a defence that it owed no duty of care to the plaintiff or, alternatively, whether it is estopped from relying on those two defences.

In his action the plaintiff claimed damages for personal injury suffered as a result of a collision at sea on 10 February 1964 between H.M.A.S. Melbourne and H.M.A.S. Voyager. The action was commenced on 2 November 1984 - over twenty years after the collision. On 14 March 1985, the Commonwealth filed its defence and admitted all the allegations in the statement of claim except the allegation that the plaintiff was injured and had suffered loss and damage. It did not plead that the action was barred by the effluxion of time, as it might have done relying on the Limitation Act. However, by an order made by the Master on 29 May 1986, the Commonwealth was given leave to file an amended defence. The amended defence denied that the collision between the Melbourne and Voyager was caused by the negligence of the officers or crew of those ships or by any other officer or servant of the Commonwealth of Australia. Indeed, par. 4 alleged that any injury suffered by the plaintiff occurred during the currency of or as a consequence of combat exercises and that consequently the naval personnel participating in the exercise owed no duty of care to the plaintiff. The amended defence also alleged that the plaintiff's action was barred by s. 5 of the Limitation Act.

On 5 June 1986 the plaintiff delivered his reply which joined issue, denied that par. 4 of the amended defence disclosed any defence to the action, and asserted that, if the defence of no duty of care or s. 5 of the Limitation Act was otherwise a defence to the action, the Commonwealth "agreed to and did waive any such defence".

Before empanelling a jury, O'Bryan J. determined the questions of law raised by the defence of no duty of care and the allegation of waiver upon the basis that the facts relied on in respect of these matters were not in issue or would not be seriously disputed at the trial. His Honour held that the defence of no duty of care was not made out and that neither the doctrine of waiver nor the doctrine of estoppel provided the plaintiff with an answer to the defence based on s. 5 of the Limitation Act. Consequently, he entered judgment in the action for the Commonwealth without empanelling a jury.

At the trial, counsel for the plaintiff identified three matters upon which he relied to constitute waiver and estoppel. They were:

A letter dated 6 September 1984 from the plaintiff's solicitors to the Secretary, Department of Defence, together with copies of other letters. The letter of 6 September stated that the plaintiff's solicitors acted on behalf of five named ex-naval personnel including Mr. Verwayen. It went on to say:

These men are in the same position as their shipmate Mr. Robert Palmer of whom we wrote to you on the 4th of July, 1983. You graciously waived the Statute of Limitations as regards Mr. Palmer and also admitted liability.

We request you treat these men the same and waive the Statute to allow us to proceed on their behalf.

The copy letters enclosed with the letter of 6 September related to another person in respect of whom the solicitor for the Commonwealth had advised the plaintiff's solicitors on 21 November 1983 "that the Commonwealth will not rely on the Statute of Limitations in this action".

(2) A conversation on 25 January 1985, between an employee of the Australian Government Solicitor and the plaintiff's solicitors, in which the employee advised that the Commonwealth proposed to admit liability and waive the Limitation Act in the plaintiff's action.

(3) The delivery of the defence on 14 March 1985 in which liability was admitted and the Limitation Act was not pleaded.

Two other matters, which do not seem to have been relied on at the trial, should be mentioned. First, on five occasions, the Australian Government Solicitor joined with the plaintiff's solicitors in applications for an expedited hearing of the claim on the ground that liability was not an issue. Secondly, on 27 November 1985 the Minister Assisting the Minister for Defence wrote to the plaintiff stating, inter alia:

As you have pointed out, the Commonwealth has admitted negligence and is not pressing the statutory limitation period as a defence. Nevertheless, it still expects claimants to show that they have suffered injury as a result of the collision between H.M.A.S. Voyager and H.M.A.S. Melbourne, and to prove the extent of their injuries and resultant loss, in order to justify an award of damages.

The reasoning of the trial judge and the Full Court

The learned trial judge held that waiver "not supported by consideration and not in respect of a valid and subsisting claim is unilateral and revocable at any time". He thought that the waiver relied upon in the present case was unilateral and voluntary and that the Commonwealth was entitled to withdraw the promise not to plead the defences. His Honour, who gave his decision before this Court's decision in Waltons Stores (Interstate) Ltd. v. Maher [45] , also rejected the claim of estoppel. He did so on the ground, inter alia, that promissory estoppel operates only in the course of an existing contractual relationship.

In the Full Court, Kaye and Marks JJ. said that "[t]he law has not recognised nor come to recognise "waiver" as a concept independent of "forbearance", waiver agreements, election, estoppel and promissory estoppel". Accordingly, their Honours held that, if the plaintiff was to succeed, he had to rely on estoppel or promissory estoppel. They held that the Commonwealth had led the plaintiff to understand that his claim would be met, that the Limitation Act would not be pleaded and that, to the knowledge of the Commonwealth, the plaintiff had relied on that promise. Their Honours said that "the application of the principles affirmed by the High Court in Waltons Stores to the facts of the present case lead to the conclusion that the respondent is not to be allowed to resile from its promise not to plead the statute". King J. held that there was no procedure whereby a right can be irrevocably abandoned "in the absence of consideration or the presence of estoppel" and that the claim of waiver failed. On the issue of estoppel, his Honour thought that the injustice to the plaintiff arising from the Commonwealth's change of position would be satisfied by "an inquiry into the out-of-pocket costs and expenses" suffered by the plaintiff as the result of that change. Subject to the payment of these sums, he held that the Commonwealth was not estopped.

In this Court counsel for the plaintiff approached the matter differently from the way in which the majority of the Full Court approached the matter. He contended that there had been a true waiver or abandonment by the Commonwealth of the right to plead the Limitation Act and "that [had] been the forefront of [his] case all along". He relied on estoppel only as an alternative answer to the defences of the Commonwealth.

Most cases which purport to apply the doctrine of waiver are really cases of contract, estoppel or election: cf. Ewart, Waiver Distributed (1917), at p. 4. Thus, for example, in Matthews v. Smallwood [46] , where a lessee had breached the condition in the lease, the question for decision was whether the lessor had abandoned his right of re-entry. Parker J. applied what he called the law of waiver and said [47] :

I think that the law on the subject of waiver is reasonably clear Waiver of a right of re-entry can only occur where the lessor, with knowledge of the facts upon which his right to re-enter arises, does some unequivocal act recognizing the continued existence of the lease. In Sargent v. A.S.L. Developments Ltd. [48] Stephen J., correctly in my opinion, treated this case as one of election. See also Kammins Co. v. Zenith Investments [49] . 1. [1910] 1 Ch. 777. 2. [1910] 1 Ch., at p. 786. 3. (1974) 131 C.L.R. 634, at p. 646. 4. [1971] A.C. 850.

Nevertheless, there are a number of cases in England and Australia which appear to hold that a party may waive a statutory condition conferred for his or her benefit. At least, some of them cannot accurately be categorized as cases of contract, estoppel or election. An early illustration is Graham v. Ingleby [50] where it was held that the plaintiff had waived the benefit of a statutory provision requiring a plea of abatement to be verified by affidavit. The defendant's affidavit in support of his plea of abatement was defective. However, by his replication the plaintiff traversed the plea, joined issue and delivered a notice of trial. The defendant then struck out the joinder of issue and delivered a demurrer to the replication. The plaintiff, after an unsuccessful application to set aside the demurrer, obtained two separate summonses for time to join issue on the demurrer. But before the time granted expired, he signed judgment in the action for want of a plea. The Court of Exchequer held that he had waived his right to treat the defendant's plea as a nullity. Parke B. said [51] :

It follows, that although an affidavit is so defective as to amount to no affidavit, a plaintiff may, if he choose, waive the benefit of his right, and join issue on the plea and go to trial; and if he does so, he cannot afterwards avail himself of the provisions of the statute. So, if he should demur to the plea, he would, in like manner, waive the benefit of the statute. If it were otherwise, the inconvenience would be great 1. (1848) 1 Ex. 651 [154 E.R. 277]. 2. (1848) 1 Ex., at p. 656 [154 E.R., at p. 279].

Graham v. Ingleby was followed in Park Gate Iron Co. v. Coates [52] which involved a statute obliging an appellant to give written notice of appeal and security for costs within ten days. Although the respondent in the case was aware that the appellant had not complied with the statute, he proceeded to settle a special case in concert with the appellant. The Court of Common Pleas held that the respondent had waived his right to rely on the statutory requirement as to notice and the giving of security within ten days. Bovill C.J. said [53] :

The provisions of s. 14, that there shall be notice of appeal and security, seem to me more in the nature of procedure and practice, and to have been intended for the benefit of the respondent. It is not a matter with which the public are concerned. If this be so, it falls within the rule that either party may waive provisions which are for his own benefit where the provisions of the Act are entirely for the benefit of the respondent, we may hold him able to dispense with their fulfilment. Brett J. said [54] : If they are conditions precedent to the jurisdiction of the Court to hear the appeal, it is clear that they cannot be waived; but if they are mere matters of procedure, and enacted entirely for the benefit of the respondent, this being a civil matter, they might be waived. 1. (1870) L.R. 5 C.P. 634. 2. (1870) L.R. 5 C.P., at p. 637. 3. (1870) L.R. 5 C.P., at p. 639.

In Ward v. Raw [55] , the defendant appealed against an order made against him but failed to give notice of his appeal within the time required. The parties appeared before a judge to settle a case for the appeal. On appeal, the plaintiff raised a preliminary objection as to the competency of the appeal. Sir Richard Malins V.C. said [56] :

Nothing is more clear to my mind than that the parties, by consenting to have the case settled and signed, have waived the objection as to time. 1. (1872) L.R. 15 Eq. 83. 2. (1872) L.R. 15 Eq., at p. 85.

In Ex parte Moore; In re Stokoe [57] , pursuant to s. 24 of the Bankruptcy Act 1869 U.K., lessors gave a trustee in liquidation a notice calling on him to disclaim a lease held by the debtor "within the usual time" (that is, twenty-eight days). On the day before the twenty-eight days expired, the lessors wrote to the trustee and asked for a reply to their letter "at [his] earliest convenience". After the twenty-eight days had expired, the trustee applied to the Court for leave to disclaim the lease. The Court of Appeal held that, by asking for a reply "at [his] earliest convenience", the lessors had waived their right to insist on an answer within twenty-eight days. Leave to disclaim was given. However, the case is really one of estoppel as the trustee obviously relied on the statement of the lessors in not answering within twenty-eight days.

In Phillips v. Martin [58] , the Full Court of the Supreme Court of New South Wales held that a party may waive a statutory right conferred for his benefit. Phillips lodged an application to bring lands under the Real Property Act 1862 N.S.W.. Within the proper time, Martin lodged a caveat to this application. Consequently, it became the duty of Phillips to state a case for the opinion and direction of the Supreme Court. Martin also had a duty to apply to the Court within three months for an order to restrain the Registrar-General from proceeding until the further order of the Court. Phillips stated his case, but Martin did not obtain an order against the Registrar-General within the specified period. After the expiration of the three-month period Phillips could have called on Martin to show cause why the caveat should not be removed. Instead, Phillips asked that Martin state a case in support of her caveat. In the case, Martin alleged that the two deeds on which Phillips relied were forgeries. These issues were tried before a jury which found the deeds were forgeries. Phillips then applied to the Full Court and subsequently to the Privy Council for a new trial but his applications failed. He then brought a summons for an order that the caveat be removed on the ground that Martin had failed to take action against the Registrar-General as required by the Act. Darley C.J. said [59] :

Here there is abundant evidence of waiver, and it is quite clear that a man may by his conduct waive a provision of an Act of Parliament intended for his benefit. The caveator was not brought into Court in any way until the caveat had lapsed. And now the applicant, after all these proceedings have been taken by him, after, doubtless, much expense has been incurred on the part of the caveator, and after lying by and hoping to get a judgment of the Court in his favour - asks the Court to do that which but for some reasons known to himself he might have asked the Court to do before any other step in the proceedings had been taken. I think he is altogether too late. It is to my mind a clear principle of equity, and I have no doubt there are abundant authorities on the point, that equity will interfere to prevent the machinery of an Act of Parliament being used by a person to defeat equities which he has himself raised, and to get rid of a waiver created by his own acts. The judgment of the Chief Justice seems to be based on some form of equitable estoppel. His Honour said [60] "we are now sitting as a Court of equity". Innes J. and Foster J. in their judgments referred to Phillips as being "estopped" from taking the point. 1. (1890) 11 N.S.W.L.R. 153. 2. (1890) 11 N.S.W.L.R., at p. 158. 3. (1890) 11 N.S.W.L.R., at p. 157.

Phillips v. Martin was approved by the Judicial Committee in Wilson v. McIntosh [61] upon which counsel for the plaintiff in the present case placed much reliance. There the appellant had lodged a caveat against land being brought under the provisions of the Real Property Act 1862 N.S.W.. More than three months after the lodging of the caveat, the respondent stated and filed a case for the opinion and direction of the Supreme Court. Later, the respondent applied for and obtained an order directing the appellant to state and file a case on her behalf. The appellant did so. No steps were taken by the respondent to obtain the decision of the Court on the questions raised between the parties. Over two years later, however, the respondent sought to have the appellant's caveat removed on the basis that she had failed to take any proceedings within three months of filing of the caveat as required by the Act and that the caveat had consequently lapsed. The Judicial Committee held that, by requiring the appellant to state her case, the respondent had waived his right to rely on the three-month limitation period. After citing the observations of Darley C.J. in Phillips v. Martin, the Judicial Committee said that they agreed with them and thought they applied to the instant case. Their Lordships went on to say [62] :

The respondent in the present case invoked the jurisdiction of the Court to compel the appellant to state her case, and the appellant did so, and no doubt incurred costs in doing so, and all the risk involved in shewing her title. If it be once admitted that an applicant may waive the lapse, it is a question of fact on the circumstances of each case whether there has been a waiver or not. 1. [1894] A.C. 129. 2. [1894] A.C., at pp. 134-135.

In Toronto Corporation v. Russell [63] , a plot of land owned by the plaintiff, an alderman of the Toronto Council, was advertised by the Council for sale for arrears of taxes. After an adjournment of the sale, the land was bought by the Council. The Council, during the adjournment, had advertised its intention to purchase the land if the amount bid was less than the arrears due but it omitted to give the plaintiff a notice in writing to this effect as required by legislation. Some years later, the plaintiff brought an action to set aside the sale on the ground, among others, that he had not received the notice. However, on the day before the land had been advertised for sale, the plaintiff, in his capacity as an alderman, had attended a meeting of the Council in which it was decided that, if the land was not sold for the arrears owing, it would be purchased by the Council at a later sale. The Judicial Committee said [1] :

There is no evidence to shew that the plaintiff, up to a short time before bringing this action, ever complained that he had not received the notice which his counsel now insist was a condition precedent to a valid sale, or that the sale was invalid for any reason. On the contrary, he treated the sale as valid, but mistook the effect of it on his right to redeem. Their Lordships think that, in the absence of all explanation by the plaintiff other than that given in his evidence on discovery, the legitimate inference to be drawn is that he consented to dispense with this notice - that is, he waived it. The basis of this decision seems to be that, at the meeting when it was decided that the Council would purchase the land if necessary, the plaintiff "had himself joined in" in conferring the power on the Council [2] . Accordingly, he waived his right to prior notice of the sale. 1. [1908] A.C. 493. 2. [1908] A.C., at p. 501. 3. [1908] A.C., at p. 499.

In Evans Pty. Ltd. v. City of Hawthorn [3] , the Full Court of the Supreme Court of Victoria held that a municipality had waived its right to object that a notice of intention to appeal, given by an aggrieved ratepayer, was not in accordance with a section of the Local Government Act 1958 Vict.. The Full Court said that the requirement of notice was intended to ensure that the municipality should not be taken by surprise [4] . It was open to the municipality, however, to elect to proceed without the information which the notice must give.

1. [1967] V.R. 212. 2. [1967] V.R., at p. 218.

In Bock v. Don-Rex Furniture (Q.) [5] , relying on Wilson , Sheahan J. held that the Workers' Compensation Board had waived its right to insist on strict compliance by the plaintiff with a section of the Workers' Compensation Act 1916 Q.. However, his Honour expressly found that the plaintiff suffered detriment which was a finding unnecessary to support a claim of waiver but essential to support a claim of estoppel.

The principle that statutory conditions enacted solely for the benefit of individuals and not for the public can be waived has also been recognised in this Court on a number of occasions: see Sandringham Corporation v. Rayment [6] ; Davies v. Davies [7] ; Brown v. The Queen [8] . In each of those cases, however, the defence of waiver failed on the facts or because the right was one enacted for the benefit of the public and not for the benefit of individuals.

1. (1928) 40 C.L.R. 510, at pp. 527, 537. 2. (1919) 26 C.L.R. 348, at p. 365. 3. (1986) 160 C.L.R. 171, at pp. 178, 208.

In my opinion, the cases to which I have referred do not establish any principle which supports the claim of waiver in the present case. Ex parte Moore and Bock , and perhaps Phillips v. Martin and Wilson v. McIntosh, are really cases of estoppel. Indeed, in Kammins Co. v. Zenith Investments Lord Diplock thought that all cases of the type to which I have referred were better categorized as estoppel cases. His Lordship said [9] :

"Waiver" is a word which is sometimes used loosely to describe a number of different legal grounds on which a person may be debarred from asserting a substantive right which he once possessed or from raising a particular defence to a claim against him which would otherwise be available to him. We are not concerned in the instant appeal with the first type of waiver. This arises in a situation where a person is entitled to alternative rights inconsistent with one another. If he has knowledge of the facts which give rise in law to these alternative rights and acts in a manner which is consistent only with his having chosen to rely on one of them, the law holds him to his choice even though he was unaware that this would be the legal consequence of what he did. He is sometimes said to have "waived" the alternative right, as for instance a right to forfeit a lease or to rescind a contract of sale for wrongful repudiation or breach of condition; but this is better categorized as "election" rather than as "waiver". It was this type of "waiver" that Parker J. was discussing in Matthews v. Smallwood [10] .

The second type of waiver which debars a person from raising a particular defence to a claim against him, arises when he either agrees with the claimant not to raise that particular defence or so conducts himself as to be estopped from raising it. This is the type of waiver which constitutes the exception to a prohibition such as that imposed by s. 29(3) of the Landlord and Tenant Act, 1954, and other statutes of limitation. The ordinary principles of estoppel apply to it.

1. [1971] A.C., at pp. 882-883. 2. [1910] 1 Ch. 777.

Some of the cases which debar "a person from raising a particular defence to a claim against him", however, stand outside the categories of election, contract and estoppel. They are sui generis. They are cases where a statute has conferred a right on A., subject to the fulfilment of a condition for the benefit of B., and B. has waived the condition by taking the next step in the course of procedure without insisting on A. fulfilling the condition. In my opinion, the true basis of the decisions in these cases is that, where the existence of a statutory right depends upon the fulfilment of a condition precedent, a person entitled to insist on the fulfilment of that condition may dispense with its compliance unless it is enacted for the benefit of the public, and that person will be held to have waived compliance with the condition if he or she knowingly takes or acquiesces in the taking of a subsequent step in the course of procedure laid down by the statute after the time for the other person to fulfil the condition has passed. These cases are also, to a certain extent, anomalous. They should be strictly confined so as not to conflict with the more established doctrines of election, contract and estoppel.

The present case, however, is far removed in nature and principle from the various cases which have given effect to the principle of waiving a statutory condition. Section 5 is not a condition precedent to the obtaining or maintaining of a statutory right by the plaintiff. Nor is the common law right of the plaintiff to sue the Commonwealth subject to the statutory condition that he commence his action within the period set by s. 5 of the Limitation Act. There is, of course, a fundamental difference between a true statute of limitation, such as s. 5, which bars stale claims and a limitation period annexed by a statute to a right which it creates. In the latter class of case, the limitation period will generally be of the essence of the right: see Australian Iron & Steel Ltd. v. Hoogland [11] . It is not a condition precedent to the right but part of it. However, neither is a true statute of limitation a condition precedent to the right which it bars. It is a plea in confession and avoidance of that right and not a condition precedent to its exercise. Accordingly, the plaintiff's common law right to bring the present action was not subject to any condition precedent that it be exercised within the period specified by s. 5 of the Limitation Act.

The deliberate act of the Commonwealth in not raising the Limitation Act or, if it matters, renouncing the defence based on that Act is not enough to attract the principle of waiver enshrined in the cases to which I have referred. That principle has nothing to say about a case where a party has done no more than consciously refuse to plead a defence or a cause of action. If, having decided not to plead a cause of action or defence, a party then seeks to amend his or her pleading before verdict, the right to amend will be governed by the principles expounded in such cases as Leotta v. Public Transport Commission (N.S.W.) [12] and Ketteman v. Hansel Properties Ltd. [13] . If the party seeks to raise the defence or cause of action after verdict, the right to amend will be governed by the principles expounded in cases such as Suttor v. Gundowda Pty. Ltd. [14] and Coulton v. Holcombe [15] . In neither case, however, will the deliberate decision not to raise the point by itself be a fatal bar to the grant of a subsequent amendment or the right to raise the defence or cause of action, and this will be so even if the party seeking to amend had previously announced his or her intention not to raise the point. In Adams v. Chas. S. Watson Pty. Ltd. [16] , this Court allowed a party to an appeal to raise a point which he had expressly conceded in the court below. Latham C.J. said [17] :

The court is of the opinion that the objection should be overruled. It is entirely a question of law. I refer to George Hudson Ltd. v. Australian Timber Workers' Union [18] , per Isaacs J., where he says: "In Ex parte Markham [19] the Court of Queen's Bench (Cockburn C.J. and Blackburn, Mellor and Lush JJ.) held that a fatal objection in law may be taken in the appellate court, though not noticed before the justices, the condition being that it could not be cured by further evidence." The principles there expressed by Isaacs J. appear to apply completely to this case. As Mr. Ashkanasy has said, it is a matter which may be taken into account in considering the question of costs, but that will depend upon the view which the court takes of the whole matter. 1. (1976) 50 A.L.J.R. 666; 9 A.L.R. 437. 2. [1987] A.C. 189. 3. (1950) 81 C.L.R. 418. 4. (1986) 162 C.L.R. 1. 5. (1938) 60 C.L.R. 545. 6. (1938) 60 C.L.R., at p. 548. 7. (1923) 32 C.L.R. 413, at p. 426. 8. (1869) 34 J.P. 150.

In Lang v. Australian Consolidated Press Ltd. [20] , the Court of Appeal of New South Wales held that a trial judge erred in leaving a defamatory imputation to the jury even though counsel for the defendant had conceded at the trial that the imputation was open to the jury to find. This Court refused special leave to appeal against the order of the Court of Appeal [21] .

1. [1970] 2 N.S.W.R. 408. 2. (1970) 124 C.L.R. 681.

Adams and Lang decide, therefore, that after verdict a party may raise a point that he has conceded in the court below. They deal with the conscious decision of counsel not to raise a point of law. It is difficult to see how they can be reconciled with the claim of "waiver" in the present case.

In the present case, the Supreme Court allowed the Commonwealth to amend its defence to plead the Limitation Act defence notwithstanding previous statements made on its behalf to the effect that the defence would not be pleaded. The facts relied on by the plaintiff in his reply of "waiver" provided no answer in point of law to that defence once it was raised. Consequently, the Supreme Court was correct in holding that the reply of "waiver" was no answer to the defence based on s. 5 of the Limitation Act.

The alternative ground upon which the plaintiff relied was that of estoppel. His counsel contended that common law and equitable estoppel are now unified. Reliance was placed on what was said by Mason C.J. in Foran v. Wight [22] See also Deane J. in Waltons [23] . However, it is unnecessary to decide that point in this case: I do not think that the doctrine of common law estoppel advances the plaintiff's case any further than does the doctrine of equitable estoppel. Both common law and equity applied the principle of estoppel in pais. They both held that, if a person made a false representation to another about a past or present fact and the representee acted upon it, the representor was not allowed to assert the untruth of that representation: Jorden v. Money [24] ; Waltons [25] . Accordingly, so far as any representation by the Commonwealth as to present or past facts is concerned, the common law doctrine of estoppel does not advance the plaintiff's case any further than the equitable doctrine does. But more importantly, in the present state of authority, the common law doctrine of estoppel does not, but the equitable doctrine of promissory estoppel does, extend to representations or assumptions concerning the future: Legione v. Hateley [26] ; Waltons [27] . Hence any representations or assumptions concerning the future can be dealt with, and on the traditional view can be dealt with only, by equitable estoppel. Even if "there is no acceptable reason why the doctrine of promissory estoppel should be seen, in a fused system, as exclusively equitable", as Deane J. asserted in Waltons [28] , the equitable rules must prevail over the common law rules "concerning the same matter": Supreme Court Act 1986 Vict., s. 29.

1. (1989) 168 C.L.R. 385, at pp. 411-413. 2. (1988) 164 C.L.R., at pp. 451-452. 3. (1854) 5 H.L.C. 185, at p. 210 [10 E.R. 868, at p. 880]. 4. (1988) 164 C.L.R., at pp. 447-448. 5. (1983) 152 C.L.R. 406, at pp. 432-435. 6. (1988) 164 C.L.R., at pp. 398-399, 459. 7. (1988) 164 C.L.R., at p. 448.

One important difference between the common law doctrine of estoppel in pais and the equitable doctrines of promissory and proprietary estoppel is that the common law doctrine is concerned with the rules of evidence, notwithstanding that a common law claim of estoppel must be pleaded, while the equitable doctrines are concerned with the creation of new rights between the parties. The common law will not permit "an unjust departure by a party from an assumption of fact which he has caused another party to adopt or accept for the purpose of their legal relations": Grundt v. Great Boulder Pty. Gold Mines Ltd. [29] . In so far as the assumed fact gives rise to a cause of action or alters the legal relationship between the parties, it does so because of the operation of the general law on the assumed fact either alone or in conjunction with other facts. Equity, like the common law, also will not permit an unjust departure from an assumption of fact which one person has caused another to adopt or accept for the purpose of their legal relations: Thompson v. Palmer [30] . But the equitable doctrines of estoppel create rights. They give rise to equities which are enforceable against the party estopped. The equitable doctrines result in new rights between the parties when it is unconscionable for a party to insist on his or her strict legal rights. It will be unconscionable for a party to insist on his or her strict legal rights if that party has induced the other party to assume that a different legal relationship exists or will exist between them, if he or she knew that the other party would act or refrain from acting on that assumption and if, as a result, the other party will suffer detriment unless the assumption is maintained. Hence, to avoid detriment to the party who has been induced to act or refrain from acting on that assumption, equity will require the parties to act on the basis of the relationship assumed by the innocent party until the detriment is removed or the innocent party otherwise compensated. The equitable right of the innocent party will take precedence over the strict legal rights of the party estopped. And because the doctrines of promissory and proprietary estoppel create equitable rights, they operate differently from the common law doctrine of estoppel in pais. The purpose of both the common law and equitable doctrines is "to avoid or prevent a detriment to the party asserting the estoppel by compelling the opposite party to adhere to the assumption upon which the former acted or abstained from acting": Grundt [31] . But because the common law doctrine of estoppel in pais is a rule of evidence, it operates to preclude the party estopped from denying the assumption of fact whenever it is necessary to do so for the purpose of determining the rights of the parties. On the other hand, because the equitable doctrines create rights, they preclude the party estopped from denying the assumption of fact (or law) only as long as the equitable right exists. Once the detriment has ceased or been paid for, there is nothing unconscionable in a party insisting on reverting to his or her former relationship with the other party and enforcing his or her strict legal rights.

1. (1937) 59 C.L.R. 641, at p. 674. 2. (1933) 49 C.L.R. 507, at p. 547. 3. (1937) 59 C.L.R., at p. 674.

What will be required to satisfy the equity which arises against the party estopped depends on the circumstances: Waltons [32] , per Mason C.J. and Wilson J. Often the only way to prevent the promisee suffering detriment will be to enforce the promise. But the enforcement of promises is not the object of the doctrine of equitable estoppel. The enforcement of promises is the province of contract. Equitable estoppel is aimed at preventing unconscionable conduct and seeks to prevent detriment to the promisee. As Brennan J. pointed out in Waltons , "in moulding its decree, the court, as a court of conscience, goes no further than is necessary to prevent unconscionable conduct" [33] . Consequently, a court of equity will only require the promise or assumption to be fulfilled if that is the only way in which the equity can be fulfilled [34] , per Brennan J. In Silovi Pty. Ltd. v. Barbaro [35] , Priestley J.A., writing for an unanimous Court of Appeal, said: "The remedy granted to satisfy the equity will be what is necessary to prevent detriment resulting from the unconscionable conduct."

1. (1988) 164 C.L.R., at p. 404. 2. (1988) 164 C.L.R., at p. 419. 3. (1988) 164 C.L.R., at p. 416. 4. (1988) 13 N.S.W.L.R. 466, at p. 472.

Despite the argument for the plaintiff to the contrary, I do not think that the present case involved any representation as to present or past facts. The Commonwealth did not represent that it had no right to plead the Limitation Act. At its highest what it did on 25 January 1985 and later was to represent that it would not plead the statute as a defence or take any steps in the future to amend its defence. If the plaintiff is to rely on estoppel, he must rely on promissory estoppel. In Waltons [36] , Brennan J. set out the matters which he thought a party must establish to prove a case of promissory estoppel. His Honour said:

In my opinion, to establish an equitable estoppel, it is necessary for a plaintiff to prove that (1) the plaintiff assumed that a particular legal relationship then existed between the plaintiff and the defendant or expected that a particular legal relationship would exist between them and, in the latter case, that the defendant would not be free to withdraw from the expected legal relationship; (2) the defendant has induced the plaintiff to adopt that assumption or expectation; (3) the plaintiff acts or abstains from acting in reliance on the assumption or expectation; (4) the defendant knew or intended him to do so; (5) the plaintiff's action or inaction will occasion detriment if the assumption or expectation is not fulfilled; and (6) the defendant has failed to act to avoid that detriment whether by fulfilling the assumption or expectation or otherwise. For the purposes of the second element, a defendant who has not actively induced the plaintiff to adopt an assumption or expectation will nevertheless be held to have done so if the assumption or expectation can be fulfilled only by a transfer of the defendant's property, a diminution of his rights or an increase in his obligations and he, knowing that the plaintiff's reliance on the assumption or expectation may cause detriment to the plaintiff if it is not fulfilled, fails to deny to the plaintiff the correctness of the assumption or expectation on which the plaintiff is conducting his affairs. 1. (1988) 164 C.L.R., at pp. 428-429.

For the purposes of the present case, I am content to adopt his Honour's analysis of the elements of equitable estoppel and I shall assume in favour of the plaintiff that the facts of this case establish the first requirement specified by his Honour. But even when that assumption is made in favour of the plaintiff, I do not think that he has made out a case of equitable estoppel.

I do not think that it is possible to infer that the plaintiff was induced to continue his action and incur unnecessary costs or that he will otherwise suffer detriment by reason of the promise that the Commonwealth would admit liability. The terms of the statement of claim, which was issued before any assurance by the Commonwealth, and the course of events since the Commonwealth changed its mind suggest that the plaintiff would have commenced and continued his action even if the liability of the Commonwealth had been put in issue from the beginning. Moreover, there is no suggestion that the plaintiff has been prejudiced in the conduct of his case by the change of position on the part of the Commonwealth. The claim of estoppel in respect of the defence of "no duty of care" must fail.

In my opinion, the claim of estoppel in respect of the Limitation Act must also fail. Ordinarily, a statement that a party does not intend to rely on a particular defence will not give rise to an estoppel. One reason is that it is difficult for a party to rely on a voluntary and unilateral promise as giving rise to an estoppel "because the promisee may reasonably be expected to appreciate that he cannot safely rely upon it": Waltons [1] , per Mason C.J. and Wilson J. Another reason is that, if the representation is confined to the party's present intention, it cannot found a promissory estoppel unless the representation, expressly or implicitly, also makes it clear that that party does not intend to change his or her mind in the future: cf. Waltons [2] , per Deane J. A statement by a party that he or she does not intend to rely upon a particular cause of action or defence cannot be regarded as anything more than a statement of present intention. Pleadings may be amended, with the leave of the court, right up to verdict. Hence, ordinarily a party cannot reasonably rely on a statement that his or her opponent will not be relying on a particular defence or cause of action to found an estoppel. Still less can the filing of statement of claim or statement of defence which omits to raise a particular cause of action or ground of defence give rise to an estoppel. The present case, however, is exceptional. First, the statement was made against the background that, in the action brought by Mr. Palmer, the Commonwealth had admitted liability and not sought to rely on the Limitation Act defence. Secondly, the statement of the Commonwealth on 25 January 1985 was made in answer to a request to "waive the Statute". The request was made before the plaintiff commenced his action. Thirdly, the Commonwealth confirmed the statement of 25 January by not pleading the Limitation Act and by not denying negligence. Fourthly, the Commonwealth joined in a number of applications for an expedited hearing of the issues after the defences were not raised. Finally, the Minister Assisting the Minister for Defence wrote to the plaintiff on 27 November 1985 pointing out that the Commonwealth "has admitted negligence and is not pressing the statutory limitation period as a defence". In these circumstances, the inevitable conclusion to be drawn is that, by 27 November 1985 at the latest, the Commonwealth was representing that it had no intention then or in the future of filing defences denying negligence or pleading the Limitation Act.

1. (1988) 164 C.L.R., at p. 406. 2. (1988) 164 C.L.R., at p. 450.

Accordingly, it is proper to infer that the plaintiff assumed from at least 27 November 1985 that his relationship with the Commonwealth as plaintiff and defendant was one in which no issue arose between them concerning the Limitation Act. I think that it is also proper to infer that the plaintiff continued his action, and incurred a liability for legal costs which he would not otherwise have incurred, because of the assurance which the Commonwealth gave concerning the Limitation Act, and that the Commonwealth knew of these matters. It follows, therefore, that, if the Commonwealth can rely on the Limitation Act to defeat the plaintiff's action, he will suffer detriment.

The plaintiff led no evidence of any particular detriment that he has suffered or will suffer by reason of being induced to alter his position as the result of the conduct of the Commonwealth. The only detriment that one can infer is that of unnecessarily incurring legal costs between the date of the assurance by the Commonwealth that it would not plead the statute and the date when the Commonwealth changed its policy. That detriment to the plaintiff can be avoided by an order for costs. It is possible that the plaintiff has suffered more worry and stress as the result of the assurance of the Commonwealth than he would otherwise have suffered if the Commonwealth had not given the assurance which it did. But the plaintiff led no evidence to this effect, and I do not think that it can be inferred. In any event, even if the plaintiff had sought to make out a case along these lines, his equity would be satisfied by an award of compensation for that additional worry and stress and would not require that the Commonwealth be estopped from relying on the Limitation Act. However, counsel for the plaintiff did not seek to make out any case for compensation on this basis. Nor did he seek an inquiry as to out-of-pocket costs and expenses as suggested by King J. He relied on estoppel as absolutely precluding the Commonwealth from relying on the Limitation Act. But, for the reasons I have given, such a claim cannot succeed. Any equity in favour of the plaintiff arising from the conduct of the Commonwealth can be satisfied by means less drastic than an order precluding the Commonwealth from relying on the Limitation Act.

The appeal should be allowed, the order of the Full Court set aside and the order of O'Bryan J. restored.