What happened
Dr Mann had practised as a surgeon in the Australian Capital Territory for many years. Between 1990 and 1991 he brought three proceedings against the ACT Board of Health, various officials and medical practitioners, alleging breach of contract and defamation. By the Health (Consequential Provisions) Act 1993 (ACT) the Board was abolished and the Australian Capital Territory, a body politic established under the Australian Capital Territory (Self-Government) Act 1988 (Cth), was substituted as the defendant. The litigation was settled on the second day of the hearing in September 1997 when Dr Mann accepted $400,000 paid into court without any admission of liability.
After settlement Dr Mann wrote to Mr Michael Moore, an Independent member of the ACT Legislative Assembly, describing the outcome as a "monumental waste of public funds" and suggesting a commission of inquiry. Mr Moore forwarded a copy of his own letter to the Chief Minister, Ms Kate Carnell, repeating the allegation and seeking assurances that such a situation would not recur. Dr Mann also told Mr Moore he had written to the Auditor-General.
On 15 December 1997 Ms Carnell replied to Mr Moore. She enclosed a letter from the ACT Government Solicitor summarising the litigation over six years and attached copies of three briefs to senior counsel and one joint memorandum of advice. The letter explained that the $400,000 settlement had been arranged to avoid the cost of a four-week hearing and had taken account of Dr Mann's capacity to meet costs if the Territory had succeeded. Ms Carnell asked Mr Moore to contact her if he had further concerns.
Evidence accepted by Miles CJ established that it was an established practice in the ACT Legislative Assembly, and in other Australian legislatures, for Ministers to provide members with confidential background information on government administration. The practice enabled members to be fully informed without the necessity of open adversarial debate. Mr Moore gave evidence that he regularly sought and obtained such information on a confidential basis and regarded it as useful in discharging his responsibilities. When he received the documents he telephoned Ms Carnell's office to confirm they were confidential. Having been told they were, he returned them without copying and wrote that he was doing so out of respect for "the agreement that has been reached between you and me".
Dr Mann, believing the enclosed documents contained defamatory imputations about him, sought their production by way of preliminary discovery under O 34A r 5 of the Supreme Court Rules (ACT). That rule permits the court to order production of a document where it is reasonable to believe the applicant may have a right to relief, further information is needed before deciding whether to commence proceedings, the respondent is likely to have possession of a relevant document, and inspection would assist the decision. O 34A r 2 provides that no order may require production of a document that, on the ground of privilege, could not be required to be produced if the applicant had already commenced proceedings.
Miles CJ held that legal professional privilege had been lost by the disclosure to Mr Moore and ordered production. He did not expressly deal with public interest immunity or discretionary factors. The Full Court of the Federal Court (Higgins, Lehane and Weinberg JJ) held that privilege had not been lost and allowed the appeal. The Full Court applied the Evidence Act 1995 (Cth) derivatively to pre-trial discovery and concluded that the disclosure fell within s 122(2)(a). Dr Mann appealed to the High Court.
The High Court (Gleeson CJ, Gaudron, Gummow and Callinan JJ, Kirby J agreeing, McHugh J dissenting) dismissed the appeal. The joint judgment held that the applicable law was the common law of legal professional privilege, not the Evidence Act, and that the confidential disclosure to Mr Moore was not inconsistent with maintenance of the confidentiality the privilege protected. The appeal was therefore dismissed with costs.
Why the court decided this way
The joint judgment began by noting that the documents were unquestionably privileged when brought into existence. The privilege was that of the Australian Capital Territory. The Chief Minister, in her capacity as head of the Executive, was entitled to see the advice and represented the Territory for that purpose. The issue was whether the privilege had been lost by the subsequent disclosure to Mr Moore.
The Court emphasised that privilege exists to enable a person to obtain legal advice without apprehension of prejudice from subsequent disclosure of the confidential communications. In the present case that purpose included, "perhaps above all", protection from disclosure to Dr Mann. The disclosure to Mr Moore was not made on terms that he was at liberty to show the documents to Dr Mann. On the contrary, it was expressly confidential. The purpose of the disclosure was to satisfy a member of the legislature that the litigation and settlement had been conducted responsibly in accordance with legal advice. It was "an understandable and natural response" to the inquiry Mr Moore had made at Dr Mann's prompting. No finding had been made that the purpose was to denigrate Dr Mann; the evidence did not support such a conclusion.
The Court rejected the proposition that any voluntary disclosure to a third party necessarily waives privilege. It cited Jordan CJ in Thomason v The Council of the Municipality of Campbelltown (1939) 39 SR(NSW) 347 at 355 that imparting advice on one occasion does not indicate an intention to waive the right to refuse disclosure on other occasions. Reference was also made to British Coal Corporation v Dennis Rye Ltd (No 2) [1988] 1 WLR 1113 and Goldman v Hesper [1988] 1 WLR 1238, which held that limited and specific disclosure to a third party for a particular purpose did not waive privilege as against an opponent in litigation. The Court noted that to describe the disclosure as simply "disclosure to a third party" was an over-simplification. Mr Moore was a member of the legislature to whom the Chief Minister was accountable. The disclosure was made in the context of the relationship between the Executive and the Legislative Assembly under the Australian Capital Territory (Self-Government) Act 1988 (Cth).
The decisive test was whether the client's conduct was inconsistent with maintenance of the confidentiality the privilege protects. The joint judgment stated at para 28: "It is inconsistency between the conduct of the client and maintenance of the confidentiality which effects a waiver of the privilege." It added at para 29 that what brings about waiver "is the inconsistency, which the courts, where necessary informed by considerations of fairness, perceive, between the conduct of the client and maintenance of the confidentiality; not some overriding principle of fairness operating at large". Applying that test, the Court concluded at para 35 that there was nothing inconsistent with the purpose of the privilege in conveying the advice on a confidential basis to a member of the Legislative Assembly who wished to consider the reasonableness of the Territory's conduct in the litigation.
The Court also held that the Evidence Act 1995 (Cth) did not govern the question. Sections 118 and 122 are expressed to apply to the adducing of evidence. Following the Court's concurrent decision in Esso Australia Resources Ltd v Commissioner of Taxation [1999] HCA 67 and its reasoning in Northern Territory of Australia v GPAO (1999) 73 ALJR 470, the common law applied to the pre-trial application for preliminary discovery. The Full Court's derivative application of the Evidence Act was therefore erroneous, although it had reached the correct ultimate conclusion.
McHugh J dissented on the ground that the privilege was that of the Executive, not the Legislative Assembly, and that disclosure to a stranger to the privilege (a member of the legislature) waived it. Kirby J agreed with the majority, emphasising the constitutional context of responsible government and the practical necessity for confidential briefings between Ministers and members.
Before and after state of the law
Before Mann v Carnell the common law test for waiver was often expressed in terms of fairness. Attorney-General (NT) v Maurice (1986) 161 CLR 475 had applied a test whether it would be unfair or misleading to allow a party to rely on material while claiming privilege over associated material. Goldberg v Ng (1995) 185 CLR 83 had extended that fairness inquiry to limited disclosure to a third party (the Law Society) under an express assurance of continued confidentiality. The Full Court in the present case had followed Adelaide Steamship Co Ltd v Spalvins (1998) 81 FCR 360 in treating the Evidence Act 1995 (Cth) as having a derivative effect on pre-trial common law privilege.
The joint judgment clarified that the touchstone is inconsistency with maintenance of confidentiality, not an overriding principle of fairness. It confined the role of fairness to informing the perception of inconsistency. It confirmed that limited confidential disclosure does not automatically waive privilege, citing Thomason, British Coal and Goldman v Hesper with approval. It also confirmed that the common law privilege is not limited to judicial proceedings (reaffirming Baker v Campbell (1983) 153 CLR 52) and that the Evidence Act provisions on client legal privilege do not apply to pre-trial discovery. The concurrent decision in Esso reinforced that the common law test for privilege itself (dominant purpose) continues to apply in federal courts notwithstanding the Evidence Act.
After Mann v Carnell the law is clearer: voluntary but confidential disclosure for a limited and specific purpose consistent with the privilege's rationale will not ordinarily constitute waiver. In the governmental context, confidential briefings to members of a legislature to explain executive action do not waive privilege. The decision has strengthened the practical operation of responsible government by permitting such briefings without automatic loss of privilege. It has also narrowed the circumstances in which fairness alone will ground waiver, requiring courts to focus on objective inconsistency.
Key passages with plain-English translation
Paragraph 28: "It is inconsistency between the conduct of the client and maintenance of the confidentiality which effects a waiver of the privilege."
Plain English: The client loses privilege only when what the client does contradicts the idea that the legal advice should stay secret. It is the contradiction, not a general sense of fairness, that matters.
Paragraph 29: "What brings about the waiver is the inconsistency, which the courts, where necessary informed by considerations of fairness, perceive, between the conduct of the client and maintenance of the confidentiality; not some overriding principle of fairness operating at large."
Plain English: Judges look for a clash between the client's behaviour and keeping the advice confidential. Fairness can help spot that clash, but fairness by itself does not decide the case. There is no free-floating fairness rule that overrides everything.
Paragraph 34: "If Mr Moore had been given copies of the legal report and advice given to the Territory in relation to the proceedings brought by the appellant upon the basis that he was at liberty to show them to the appellant, (even if to nobody else), that would have waived the privilege, because it would have been inconsistent with the confidentiality protected by the privilege."
Plain English: If the government had let the MLA show the documents to Dr Mann, that would have destroyed the privilege. But that is not what happened. The documents were given on strict confidence and could not be shown to Dr Mann.
Paragraph 35: "The purpose of the privilege being to protect the Territory from subsequent disclosure of the legal advice it received concerning the litigation instituted by the appellant, there was nothing inconsistent with that purpose in the Chief Minister conveying the terms of that advice, on a confidential basis, to a member of the Legislative Assembly who wished to consider the reasonableness of the conduct of the Territory in relation to the litigation."
Plain English: The whole point of the privilege was to stop Dr Mann seeing the advice. Giving it privately to the MLA to let him check that the government had acted properly did not undermine that point. Therefore the privilege survived.
These passages crystallise the shift from a broad fairness inquiry to a focused inconsistency test and illustrate its application to the specific constitutional setting of the ACT.
What fact patterns trigger this precedent
Mann v Carnell is triggered when a client (including a government) voluntarily discloses the substance or copies of privileged legal advice to a third party on an express or implied understanding of confidentiality, for a limited purpose, and that disclosure is not inconsistent with the confidentiality the privilege was intended to protect. Typical triggers include:
- A Minister providing legal advice confidentially to a backbench or independent member of parliament to explain executive action and avoid open debate (as occurred here at paras 12-14).
- Limited disclosure to a regulator, professional body or other person under an express assurance that confidentiality will be maintained and the material will not be used against the client.
- Any case where the recipient is not free to pass the material to the opposing party in anticipated litigation.
The precedent does not apply where the disclosure is made on terms that the recipient may show the material to the opponent, or where the disclosure is made in open court, or where the client puts the privileged advice in issue in litigation. It also does not apply where the Evidence Act 1995 (Cth) or its State equivalents directly govern the adducing of evidence; in those situations ss 118 and 122 supply the statutory test. Because the decision rests on common law principles, it applies in all pre-trial contexts and in jurisdictions without equivalent evidence legislation. The constitutional context of responsible government is not essential; the core inconsistency test is of general application.
How later courts have treated it
The judgment itself treats earlier authorities as consistent with its central proposition. It cites Goldberg v Ng (1995) 185 CLR 83 at para 30 but does not overrule it; instead it reads the case as not supporting the proposition that any voluntary disclosure necessarily waives privilege. It approves the reasoning in Attorney-General (NT) v Maurice (1986) 161 CLR 475 at para 28 but confines the fairness test to its role in assessing inconsistency. It follows its own concurrent decision in Esso Australia Resources Ltd v Commissioner of Taxation [1999] HCA 67 at para 27 in holding that the Evidence Act does not derivatively govern pre-trial privilege questions. It cites Baker v Campbell (1983) 153 CLR 52 at para 19 to affirm the breadth of common law privilege beyond court proceedings. It refers to British Coal Corporation v Dennis Rye Ltd (No 2) and Goldman v Hesper as illustrating that limited specific disclosure does not waive privilege against an opponent.
Because the decision is a unanimous High Court authority on the common law test (McHugh J dissented only on the application to the governmental facts, not on the statement of principle), later courts are bound by the inconsistency test. The judgment has been treated as settling that fairness is not an independent overriding criterion and that confidential limited disclosure for accountability purposes does not automatically waive privilege. The Court expressly left open any argument that the Evidence Act might indirectly affect discretion in preliminary discovery, noting at para 27 that no such argument had been advanced.
Still-open questions
The joint judgment left several matters unresolved. First, it did not decide whether public interest immunity could have protected the documents. Miles CJ had not expressly ruled on the point and the Full Court found it unnecessary to do so. The evidence led from senior public servants about the convention of confidential briefings was noted at paras 12 and 56-58 but not ruled upon. The Court observed at para 8 that the question under s 130(4)(f) of the Evidence Act had not been fully argued.
Second, the precise boundary between the common law and the Evidence Act in jurisdictions where the Act applies remains nuanced. Although the derivative approach was rejected, the Court noted at para 27 that an argument might have been available that inability to prove the documents' contents at trial would be a discretionary reason to refuse preliminary discovery. That argument was not run and is therefore still open.
Third, the Court did not explore the full implications of the separation of powers under the Australian Capital Territory (Self-Government) Act 1988 (Cth) for privilege ownership. McHugh J's dissenting analysis that the privilege belonged exclusively to the Executive and that the Legislative Assembly was a stranger to it was not adopted by the majority. The majority treated the disclosure as made by the client (the Territory) through its Chief Minister without deciding whether the Assembly could ever be regarded as sharing ownership of the privilege.
Fourth, the precise degree of "inconsistency" required in non-governmental contexts remains fact-sensitive. The Court gave the example at para 34 that disclosure on terms that Mr Moore could show the documents to Dr Mann would have waived privilege, but gave no exhaustive list of other circumstances that might cross the line. Later courts must continue to apply the inconsistency test case by case.
Finally, the interaction between parliamentary privilege, public interest immunity and legal professional privilege in legislative oversight remains undeveloped. The Court noted the practice of confidential briefings but did not decide whether such communications could attract parliamentary privilege or a distinct head of public interest immunity. These questions were left for future litigation.
The decision has therefore settled the core common law test for waiver while leaving room for further refinement at the intersection of executive accountability, public interest immunity and statutory evidence regimes. Practising lawyers should advise clients that confidential limited disclosure for accountability or regulatory purposes will usually be safe, but must still scrutinise the exact terms of any disclosure to ensure no inconsistency with the original privileged purpose is created.