Assuming, contrary to the opinion already expressed, that the requirement that the action must be commenced within twelve months is not an ingredient in the cause of action but merely bars the remedy if pleaded, the appellant would not be in any better position. Where the question arises whether a statute has a retrospective operation, it is usual to divide statutes into two classes, the one where the new statute affects existing substantive rights and the other where it affects only the existing practice and procedure of the courts for enforcing such rights. The distinction between the two kinds of statutes was explained by Dixon J. (as he then was) in Kraljevich v. Lake View & Star Ltd. [2] . His Honour said: "The presumptive rule of construction is against reading a statute in such a way as to change accrued rights the title to which consists in transactions passed and closed or in facts or events that have already occurred. In other words, liabilities that are fixed, or rights that have been obtained, by the operation of the law upon facts or events for, or perhaps it should be said against, which the existing law provided are not to be disturbed by a general law governing future rights and liabilities unless the law so intends, appears with reasonable certainty. But, when the alteration in the law relates to the mode in which rights and liabilities are to be enforced or realized, there is no reason to presume that it was not intended to apply to rights and liabilities already existing and its application in reference to them will depend rather upon its particular character and the substantial effect that such an operation would produce" [3] . Statutes of limitation are often classed as procedural statutes. But it would be unwise to attribute a prima facie retrospective effect to all statutes of limitation. Two classes of case can be considered. An existing statute of limitation may be altered by enlarging or abridging the time within which proceedings may be instituted. If the time is enlarged whilst a person is still within time under the existing law to institute a cause of action the statute might well be classed as procedural. Similarly if the time is abridged whilst such person is still left with time within which to institute a cause of action, the abridgment might again be classed as procedural. But if the time is enlarged when a person is out of time to institute a cause of action so as to enable the action to be brought within the new time or is abridged so as to deprive him of time within which to institute it whilst he still has time to do so, very different considerations could arise. A cause of action which can be enforced is a very different thing to a cause of action the remedy for which is barred by lapse of time. Statutes which enable a person to enforce a cause of action which was then barred or provide a bar to an existing cause of action by abridging the time for its institution could hardly be described as merely procedural. They would affect substantive rights. The two cases to which we were specially referred, R. v. Chandra Dharma [1] and The Ydun [2] were cases where the statutes in question were passed whilst in the former case the prosecution and in the latter case the action could still be brought under the existing law. In R. v. Chandra Dharma [1] a prosecution was commenced for an offence which at the time of its commission had to be commenced within three months. Before the three months had elapsed the time for commencing the prosecution was extended to six months. The prosecution was commenced more than three months but less than six months after the commission of the offence. The accused was convicted of the offence and it was held that the conviction must be upheld because the Act extending the time for launching the prosecution related to procedure only and was therefore retrospective. Channell J., one of the judges, said that if the time under the old Act had expired before the new Act came into operation the question would have been entirely different, and it would not have enabled a prosecution to be maintained even within six months from the offence. It may be that the other judges, Lawrance J., Kennedy J. and Phillimore J. did not accept this view. They all agreed with the judgment of Lord Alverstone C.J. who said: "when no new disability or obligation has been created by the statute, but it only alters the time within which proceedings may be taken, it may be held to apply to offences completed before the statute was passed. That is the case here. This statute does not alter the character of the offence, or take away any defence which was formerly open to the prisoner. It is a mere matter of procedure, and according to all the authorities it is therefore retrospective" [3] . But it would be difficult to say that the amending statute would not have taken away any defence which was formerly open to the prisoner if it had not been passed until after the period of three months had expired. It would appear that this passage from Lord Alverstone should be read, like all judicial utterances, in the light of the particular facts and that his Lordship may not have intended his remarks to apply to such an event. The case of The Ydun [1] is the opposite case. There the plaintiffs had a cause of action for damages against a public authority which occurred on 13th September 1893. The Public Authorities Protection Act 1893, which was passed on 5th December 1893, and came into force on 1st January 1894, provided that actions against public authorities for any alleged neglect or default must be commenced within six months next after the act, neglect or default complained of. The plaintiffs did not commence their action until 14th November 1898 and it was held that the Public Authorities Protection Act was retrospective as it dealt with procedure and the plaintiff's action was barred six months after 13th September 1893. Accordingly it applied to all causes of action brought after its commencement whether they arose before or after 1st January 1894. In that case the statute shortened the time within which the plaintiffs could bring their cause of action but still left them with sufficient time within which to institute it after the statute came into force. The case of Coleman v. Shell Co. of Australia [2] was a similar case in principle to R. v. Chandra Dharma [3] and The Ydun [1] . The statute extending the time within which certain proceedings might be taken was held to apply to a cause of action arising before it was passed. But the cause of action could still have been brought under the existing law because, although the plaintiff was out of time as of right, the Court had power for a limited period which had not expired to extend the time. The present case is distinguishable from these three cases because the period within which the plaintiff could commence the action under the existing law had expired before s. 2 (a) of the Compensation to Relatives (Amendment) Act 1953 was enacted. It could be said of the statutes under consideration in these three cases, to use the words of the President (Sir F. H. Jeune) in The Ydun [1] , "that the interference with vested rights suggested in this instance is hardly appreciable" [4] . But when an existing cause of action is barred by lapse of time under the existing law it could not be said that the effect upon existing legal relationships of a statute extending the time within which the cause of action might be brought would be "hardly appreciable". The right to enforce a cause of action (sometimes called an accrued claim) is an existing substantive right: Gillmore v. Executor of Shooter [5] ; Henshall v. Porter [6] ; Brueton v. Woodward [7] . It is of the same character as the right to prosecute an appeal which was held by the Privy Council in Colonial Sugar Refining Co. v. Irving [1] to be in this category. There can be no distinction in principle between a right given by law to commence an action and a defence given by law which bars an action. A law which has the effect of taking away such a right or immunity could not be classed as merely procedural. Procedural statutes are statutes which regulate the procedure and practice of the courts: Wright v. Hale [2] . The Statute of Frauds and Lord Tenterden's Act are examples of statutes which relate to procedure but they have been held to affect substantive rights and therefore to be prima-facie statutes which should not be construed as having a retrospective operation. In Gillmore v. Executor of Shooter [3] decided in 1677, it was held that the Statute of Frauds did not apply to actions brought after to enforce agreements made before it became law. In 1678, one year later, Lord Nottingham in Ash v. Abdy [4] was firmly of the same opinion. In Towler v. Chatterton [5] Lord Tenterden's Act was construed by Park J. as having a retrospective effect but only because the operation of the Act was postponed for about eight months so that creditors who were affected by it would have an opportunity of enforcing their claims in the interval under the law as it stood before the passing of the Act. In Doe d. Evans v. Page [6] it was held that s. 7 of the Limitation Act 3 & 4 Wm. IV c. 27, was not retrospective and did not apply to tenancies at will which had determined before the passing of the Act. Lord Denman said: "A different construction, even if the words permitted it, would cause the greatest hardship: for a person, who, as the law stood before the passing of the Act, was in ample time to bring his ejectment and recover property that undoubtedly was his, would by the operation of the statute be suddenly deprived of the means of asserting his right, there being no clause for the postponement of the operation of the statute for such a period as would enable persons, who would be otherwise affected by it, to assert their rights" [7] . See also Doe v. Angell [8] ; Doe v. Bold [9] . Williams v. Mersey Docks and Harbour Board [10] is an example of how a statute of limitations can affect proceedings under Lord Campbell's Act. It was held that the injured person, the deceased husband of the plaintiff, would have been barred by the Public Authorities Protection Act 1893 if he had sued the defendant when alive and the widow who sued under Lord Campbell's Act was also barred. Cozens-Hardy L.J. said: "In the present case the deceased could not at the date of his death, or at any time after the lapse of six months from his injury, have maintained an action in respect of that injury against the defendants; and therefore his representative cannot maintain this action" [1] . An instance in this Court of a statute relating to procedure which was held to affect a substantive right and for that reason not to have a retrospective operation will be found in Newell v. The King [2] . It is presumably because the right to plead a statute of limitations as a bar to an action is considered to be a matter of substance and not a mere matter of practice or procedure that the courts have adopted the principle already mentioned that no amendment should be made to a writ which will enable an action to be maintained which at the date of the application was out of time. This is borne out by many judicial statements of which it will suffice to cite a few. In Doyle v. Kaufman [3] , (affirmed) [4] Cockburn C.J., with whom Lush J. concurred, said that a writ should not be renewed "when by virtue of a statute the cause of action is gone" [5] . In Battersby v. Anglo-American Oil Co. Ltd. [6] Lord Goddard, delivering the judgment of the Court of Appeal, said of this statement "Perhaps it might have been more accurate to say "when the remedy is barred," but the effect is the same" [7] . In Smalpage v. Tonge [8] Cotton L.J. referring to Doyle v. Kaufman [3] said "There the right of action was gone". In Hewett v. Barr [9] Lord Esher M.R. said that amendments "ought not to be granted where they would have the effect of altering the existing rights of the parties" [10] . In Mabro v. Eagle, Star & British Dominions Insurance Co. Ltd. [11] Scrutton L.J. said: "The Court has never treated it as just to deprive a defendant of a legal defence" [12] and Greer L.J. said: "It has been the accepted practice for a long time that amendments which would deprive a party of a vested right ought not to be allowed" [13] .