Public Meaning and Private Communications: A Sidebar to Ravbar
20.08.2025
The High Court’s decision in Ravbar v Commonwealth [2025] HCA 25 raises a number very large questions, including as to proportionality testing in different fields of constitutional law, ‘reading down’ constitutional purposes, and the constraints of precedent on a single Justice of the High Court. In amongst those headline matters one might easily overlook another issue that divided members of the Court – the relevance of private communications to the interpretation, and judicial review, of legislation. This issue might seem niche, but the use of private documents in legislative deliberation is in fact relatively common.
Almost every law will have been generated by reference to drafting instructions and draft legislation, which usually remain confidential and/or privileged (unless obtained through freedom of information or court processes). Similarly, Cabinet documents may tell one much about the motivation behind a particular law’s introduction into Parliament, although they too will ordinarily remain confidential, at the Commonwealth level, for 30 years. Perhaps more unusually, history provides examples of entire sittings of Parliament being held in secret, and some speeches not being formally recorded, only for informal notes to later be released in book form. In light of these practices – some more common than others – it is somewhat surprising that the High Court had not previously pronounced authoritatively on the relevance of private communications to the interpretation, and judicial review, of legislation. It is also somewhat surprising that, when the Court was called to address this issue in Ravbar, it was dealt with in little detail, and without reference to a number of previous authorities – from Australia and abroad – touching on the subject. This post will survey some of those authorities and show that they suggest a slightly different approach to that suggested by the High Court. On this approach, the relevance of private communications will depend on whether the Court is: (1) interpreting the law to ascertain its meaning and application, in which case private communications will generally be irrelevant; or (2) ascertaining the purpose for which the law was enacted in order to test its validity against a purpose-based constitutional limit, in which case private communications may be relevant.
The way the issue arose in Ravbar
In Ravbar, the plaintiffs challenged legislation under which the Construction and General Division of the Construction, Forestry and Maritime Employees Union (‘CFMEU’) had been placed into administration on a number of bases, one of which was the implied freedom of political communication. (The other bases of challenge are not presently relevant, as they did not give rise to issues of the use of private communications.) One aspect of the plaintiffs’ implied freedom challenge required the Court to inquire as to the purpose of the impugned statutory regime, and in particular, ‘whether its purpose is legitimate in the sense of being compatible with the maintenance of the constitutionally prescribed system of representative government’: at [27] per Gageler CJ.
It was in this context that the plaintiffs relied on two letters that apparently, until the litigation, were not in the public domain. The first was a letter dated 14 August 2024 from Senator Watt, as Minister for Employment and Workplace Relations, to Senator Cash, as Deputy Leader of the Opposition in the Senate. That letter recorded a qualified commitment of the Government, should the legislation be enacted, to consider a scheme of administration under which the relevant division of the CFMEU would be limited in the donations it could make to political parties. The second was a letter from Mark Irving KC, as the administrator of the scheme of administration, to Senator Watt dated 19 August 2024 forecasting the type of administration he intended to run, should he accept the appointment, which included as a guiding principle that ‘[t]he union will not engage in party politics during the administration: donations; positions at political party conferences; promotion of particular candidates’.
The two letters were said to support the plaintiffs’ case that one purpose of the legislation was to ban the relevant division of the CFMEU from making political donations and engaging in political activity. The argument was put in the following forceful terms in the plaintiffs’ written submissions:
This case is a stark reminder that ‘you cannot do indirectly what you are forbidden to do directly’. The Bill passed the Parliament without any provision precluding political activity or donations by the C&G [Construction & General] Division [of the CFMEU]. Such a provision would have been patently invalid for having an illegitimate purpose. Hoping to avoid this problem, the Parliament passed the Bill with the assurance of the Administrator that he intended to preclude such activity and donations and without including any provision to curtail or stop him from doing so. The Parliament thus sought to escape its constitutional limits through this disingenuous device but regard to those aspects of the legislative history and mischief reveal the illegitimate legislative purpose. It is therefore invalid no less than had the Parliament proceeded in a more open and direct fashion. (citation omitted)
The defendants’ argument in response was put similarly forcefully. It was said that the letters (and other material relied upon by the plaintiffs) ‘have no legitimate role in ascertaining Parliament’s purpose’. The various members of the Court reached similarly polar positions.
The judgments on this issue in Ravbar
Gageler CJ held that when ascertaining the purpose of a law, just as when ascertaining its meaning, there was ‘no reason in principle’ to limit the inquiry to the ‘contemporaneous public record’: at [45]. Accordingly, Gageler CJ relied upon the letters (and other matters) as a ‘sufficient basis from which to infer a qualified form of the additional legislative purpose for which the plaintiffs argued, being the suppression of political donations and activity’: at [57]. Ultimately, however, because Gageler CJ viewed that purpose to be qualified, he did not consider it to render the legislation invalid (the way in which Gageler CJ framed this qualified purpose was another issue on which the Justices disagreed, but is beyond the scope of this post).
Gordon J took a very different view. Her Honour held private communications only formed part of the extrinsic materials, and could thus only be considered, to the extent they were referred to in public (for example, in parliamentary debates) in connection with the enactment of the legislation. Gordon J continued: ‘Otherwise, it is impermissible to have regard to the private letters. The meaning of an Act cannot be determined by reference to material that will, by reason of its private nature, not be available to all who may need to ascertain that meaning.’: at [137]. For Gordon J, this position was consistent with the type of material listed in s 15AB(2) of the Acts Interpretation Act 1901 (Cth). Ultimately, Gordon J was not prepared to accept the legislative purpose advanced by the plaintiffs. Steward J specifically agreed with Gordon J’s approach to ‘the correct and orthodox discernment of legislative intent and the proper use of extrinsic materials’: at [270]. Gleeson J also generally agreed with Gordon J’s analysis: at [305].
Edelman J was prepared to accept a very limited use for private materials in the process of statutory interpretation, namely, ‘as evidence of matters that are widely known to the public’: at [175]. However, his Honour strongly rejected any wider use of such materials, explaining:
If the legal meaning of a statutory provision were altered due to matters in private material that are not known to the general public at the time the provision is enacted, and perhaps for many years subsequently if the material remains private, then that legal meaning might be unascertainable by any member of the public other than the parties to the private material. Such a conclusion is anathema to the transparency required in any society ordered by law. And it would turn upon their head the fundamental principles of public intelligibility that motivate the interpretation of legislation. ([176], citation omitted)
As has been noted above, Gleeson J generally agreed with Gordon J: at [305]. Gleeson J also expressed her agreement with the Commonwealth’s submissions as to the purpose of the statutory scheme, and agreed with Beech-Jones J’s analysis rejecting the plaintiffs’ contention of an additional and illegitimate purpose of the scheme: at [308]. In this respect, Beech-Jones J referred to the second letter and noted that the references to that letter in parliamentary debate ‘may suffice to enable the letter to be relied on for the purposes of ascertaining the purpose of Pt 2A’: at [466], emphasis added. Ultimately, however, his Honour did not decide this point because, even on the assumption that letter could be relied upon, his Honour held that the letter did not ‘properly reflect the effect’ of the statutory scheme: at [466].
Jagot J remarked that ‘[i]t may be accepted that legislative purposes are not to be divined from private communications’: at [377]. However, her Honour was prepared to infer from the other objective circumstances that one of the purposes of the legislation was to ensure that the relevant division of the CFMEU ‘would not engage in political activities, including political communications’: at [377].
In the final analysis then, at least four of the Justices (Gordon, Edelman, Steward and Jagot JJ) rejected the use of private communications, although Edelman J allowed for very limited circumstances in which private communications might be relevant evidence of public meaning (analogous to a dictionary). Gleeson J might be added to that group, although her Honour also agreed with Beech-Jones J, who expressly did not decide the issue. Gageler CJ was alone in holding that private communications could inform the divination of legislative purpose.
One unusual aspect to the treatment of this issue in Ravbar is that various judgments made very little reference to authority. It seems likely that this was because the question was just one issue in a case that threw up many, and that time and space constraints meant that the issue was not dealt with in detail in the parties’ written or oral submissions. Now, with the luxury of time and the benefit of the judgments, it is worth reviewing those past authorities. What emerges from them is a bifurcated approach depending on whether the Court is: (1) interpreting legislation to ascertain its meaning; or (2) discerning the purpose of legislation to test its validity against a purpose-based limit on legislative power. In the former circumstances, the authorities are against having resort to private communications; however, there is at least some support for having regard to private communications in the latter context.
Impermissible to have regard to private communications to ascertain statutory meaning
The only authority cited in the High Court on this issue was Wong v The Commonwealth [2009] HCA 3; (2009) 236 CLR 573, which was raised for the first time in Ravbar in the plaintiff’s reply submissions on the second day of the hearing (it was not cited in the written submissions). The judgments in Wong refer in passing to a legal advice to government on the meaning of an amendment to a bill for a referendum on what became s 51(xxiiiA) of the Constitution: see [50]-[55], [277]. Plainly, that advice would have been privileged at the time of the bill’s passage, and at the time of the referendum. However, as Edelman J noted in Ravbar, the better understanding of Wong is that the privileged advice was only used to shed light on the original public meaning of statutory words: [175], cf [45] per Gageler CJ. In any event, the issue does not seem to have been the subject of argument in Wong.
More directly on point, but not referred to in Ravbar, is the statement in Black-Clawson International Ltd v Papierwerke Waldhof-Aschaffenburg AG [1975] AC 591 at 614 where Lord Reid suggested:
An Act is addressed to all the lieges and it would seem wrong to take into account anything that was not public knowledge at the time. That may be common knowledge at the time or it may be some published information which Parliament can be presumed to have had in mind.
Jacinta Dharmananda has described this as a common law ‘limitation’ on the use of extrinsic materials, and suggested that while it ‘has not been clearly expressed as a principle in Australia, … there is evidence of the restriction being applied in the case law’. It may in fact be debateable whether the authorities cited by Dharmananda apply the principle, or are simply consistent with it. Perhaps the closest that the courts have come to supporting the principle was in Linfox Australia Pty Ltd v Commissioner of Taxation of the Commonwealth of Australia [2019] FCAFC 131; (2019) 271 FCR 365, where one of the reasons for finding that purported extrinsic materials were not capable of assisting was that ‘that material would not have been before the legislature’: [117] per curiam.
As Dharmananda also notes, however, if one turns from matters of authority to basal legal principle, there are cogent arguments against the use of private materials in statutory interpretation. For example, Larry Alexander treats the issue as one that is determined by the institutional logic of rational communication between Parliament and the people to whom it is speaking. Alexander writes: ‘no rational communicator can be said to have intended an uptake while aware that her target audience lacked the evidence necessary to infer that intended uptake’. A separate, normative, argument can be made by reference to a bundle of ideas associated with the rule of law, including the clarity, certainty, predictability and intelligibility of law to the public. If private communications were to legitimately inform statutory meaning then the unavailability of that material to the general public would result in circumstances where the public cannot accurately gauge the meaning of laws, and may unwittingly act in breach of them (and thereby be exposed to penalties). Such a result would be contrary to a normative rationale for the rule of law, which holds that law better advances the dignity of individuals as agents when it enables them to make informed decisions about their actions. Such a result would also cut against the instrumental rationale for the rule of law, which holds that laws that are clear, certain, predictable and intelligible will more successfully guide human conduct (for example by deterrence). These ideas appear to be what Edelman J was gesturing to in Ravbar when his Honour said: ‘Such a conclusion is anathema to the transparency required in any society ordered by law. And it would turn upon their head the fundamental principles of public intelligibility that motivate the interpretation of legislation.’: at [176].
Permissible to have regard to private communications to invalidate statute for unconstitutional purpose
There is, however, at least some support in authority for the idea that a different approach might be warranted when the Court is tasked not with interpreting legislation to determine its meaning, but with ascertaining the purpose of a law so as to measure it against a purpose-based constitutional limit on power. In Deputy Federal Commissioner of Taxation v W R Moran Pty Ltd [1939] HCA 27; (1939) 61 CLR 735 at 793, Evatt J suggested:
In considering the question of admissibility of evidence, a fundamental distinction has to be drawn between cases where the court has no function committed to it except that of interpreting a statute, and cases where, in accordance with a constitutional charter, the court has to determine whether there has been an infringement by the legislature of some overriding constitutional provision. In the former case, the court's function is to interpret the language which the legislature has employed, though, even there, the court is not bound to shut its eyes to public general knowledge of the circumstances in which the legislation was passed.
In the latter case, the court may entirely fail to fulfil its duty if it restricts itself to the language employed in the Acts which are challenged as unconstitutional. …
Admittedly, his Honour’s views were expressed at a time when there was much stricter limits placed on the use of extrinsic materials. Nevertheless, Evatt J’s suggestion echoes in the way the plaintiffs in Ravbar ultimately tried to put their point orally, albeit only in reply and without much authority in support. Bret Walker SC there drew a distinction between a Court’s task of ‘understanding what a statute means’ (i.e. interpreting it in order to discern its application) and ascertaining its ‘purpose which may or may not have … a destructive effect upon its validity under the Constitution’. The point Mr Walker seems to have been getting at, like Evatt J, is that where a limit on legislative power is fixed by reference to the purpose, not just the effect, of legislation, the policing of that limit on power ought to proceed by reference to the best evidence of legislative purpose, not evidence that might artificially shield the legislation from challenge.
This approach would not create any of the above-discussed rule of law concerns law that are raised when reliance is had on private documents in the course of interpreting a law to determine its application. That is because, on this approach, private documents would remain incapable of informing the meaning of the law for the purposes of its application to the public. However, the availability of such documents in a validity inquiry would ensure that judicial inquiries into whether Parliament had a constitutionally offensive purpose do not proceed blind to what may be the best evidence of that purpose. Justice Evatt’s ‘fundamental distinction’ thus appears to offer a middle course between the polar positions in Ravbar. Applying Evatt J’s distinction, the permissibility of reference to extrinsic materials would depend on the purpose of the Court’s inquiry, and particularly whether it is enforcing a purpose-based limit on legislative power or whether it is interpreting legislation to ascertain, and apply, its meaning. It remains to be seen whether this more nuanced approach to private communications ultimately finds favour with the High Court.
Julian R Murphy is a Barrister at the Victorian Bar and an Honorary Fellow at Melbourne Law School. He is the author of the forthcoming Constitutionally Protective Statutory Interpretation (Federation Press, 2025).
Suggested citation: Julian R Murphy, ‘Public Meaning and Private Communications: A Sidebar to Ravbar’ (20 August 2025) <https://www.auspublaw.org/blog/2025/08/public-meaning-and-private-communications-a-sidebar-to-ravbar>