Parliamentary privilege was established for the purposes of protecting Members of Parliament from being prosecuted or penalised for what they debated in Parliament or from being controlled by the executive in what they were permitted to debate. It is a key pillar in supporting the constitutional principle of responsible government and the accountability of Ministers to Parliament. Yet in recent times, in the United Kingdom in relation to prorogation and in Australia in relation to the reports of the Auditor-General, the executive has sought to rely on parliamentary privilege as a weapon to prevent Parliament from holding Ministers to account. Can parliamentary privilege be perverted in its use to achieve the complete opposite of its purpose?

The purpose of parliamentary privilege

Parliamentary privilege is derived from the long struggle between Parliament and the monarch in the United Kingdom. In both the United Kingdom and Australia it finds its continuing source in article 9 of the Bill of Rights 1689. It provides:

That the Freedom of Speech and Debates or Proceedings in Parliament ought not to be impeached or questioned in any Court or Place out of Parliament.

The catalyst for article 9 was the case of R v Eliot, Holles and Valentine (1629) 3 St Tr 294, in which three Members of Parliament were prosecuted during the Reign of King Charles I for allegedly seditious statements they made in Parliament. These statements concerned complaints of illegal taxation. The Members were imprisoned in the Tower of London, where Sir John Eliot died in 1632 and the other two were detained for 11 years. In 1668 Eliot’s conviction was reversed by the House of Lords, which regarded it as illegal and against the freedom and privilege of Parliament. This was reinforced in 1689 with the assertion of freedom of speech and debate in article 9 of the Bill of Rights.

The one essential purpose of parliamentary privilege, according to Enid Campbell, is to enable the ‘Houses of Parliament and their members to carry out their functions effectively’ (at 1). For example, Lord Phillips in R v Chaytor [2011] 1 AC 684 said that one must look to the connection between the claimed privileged activity and parliamentary proceedings and consider whether the absence of protection would be ‘likely to impact adversely on the core or essential business of Parliament’ (at [47]).

Parliamentary privilege does not have the purpose of preventing the Houses from receiving information or debating issues. On the contrary, it protects the power of the Houses to debate what they wish. Nor does parliamentary privilege have the purpose of protecting the executive against scrutiny by the Houses or the courts. For example, as Lord Mance pointed out at [17] in Toussaint v Attorney General of St Vincent and the Grenadines [2007] 1 WLR 2825, the tabling and approval of regulations in Parliament does not prevent courts from reviewing the validity of a regulation made by the executive. Merely announcing an executive decision in Parliament does not immunise the making of that decision from judicial review. It must still be made within power and in accordance with all procedural requirements.

When construing the scope of article 9 of the Bill of Rights, courts have taken into consideration its history and its purpose. Lord Browne-Wilkinson in Pepper v Hart [1993] AC 593 said of article 9 at 638 that:

It ensures the ability of democratically elected Members of Parliament to discuss what they will (freedom of debate) and to say what they will (freedom of speech)….

In my judgment, the plain meaning of article 9, viewed against the historical background in which it was enacted, was to ensure that Members of Parliament were not subjected to any penalty, civil or criminal for what they said and were able, contrary to the previous assertions of the Stuart monarchy, to discuss what they, as opposed to the monarch, chose to have discussed.

Yet executive governments today still seek to limit what Parliaments can debate and when they can do it, and even seek to employ parliamentary privilege to help them do so.

Using privilege to prevent judicial review of prorogation in the United Kingdom

The first example concerns the prorogation of Parliament in the United Kingdom for five weeks in the critical period leading up to the date of 31 October 2019, upon which the United Kingdom was then scheduled to leave the European Union. When judicial review was sought of the legality of the advice to the Queen to prorogue Parliament, the UK Government responded that as prorogation was given effect by Lords Commissioners representing the Queen during a ceremony before both Houses assembled in the House of Lords, it was a parliamentary proceeding and its validity could not be questioned by a court.

The UK Supreme Court, in R (Miller) v Prime Minister [2019] UKSC 41, rejected this argument at [68]. Following the earlier precedents mentioned above, the Court looked to the core business of Parliament and the protection of freedom of speech. Their Lordships concluded that prorogation could not ‘sensibly be described as a “proceedings in Parliament”’ for the purposes of article 9:

It is not a decision of either House of Parliament. Quite the contrary: it is something which is imposed upon them from outside. It is not something upon which the Members of Parliament can speak or vote. The Commissioners are not acting in their capacity as members of the House of Lords but in their capacity as Royal Commissioners carrying out the Queen’s bidding. They have no freedom of speech. This is not the core or essential business of Parliament. Quite the contrary: it brings that core or essential business of Parliament to an end.

Hence, even though as a matter of form, prorogation was given effect through words spoken during parliamentary proceedings, in substance it did not fall within the purpose of article 9 of the Bill of Rights and the protection afforded by parliamentary privilege. The unanimous decision of 11 Law Lords in dismissing the privilege argument definitively provides a powerful precedent for the future.

Using privilege to prevent debate of an Auditor-General’s report in Australia

In Australia the same underlying issue has arisen in a different context. In 2018 the Commonwealth Attorney-General granted a certificate under s 37(1)(b) of the Auditor-General Act 1997 (Cth) to prevent the Auditor-General including certain facts, analysis and conclusions in his public report on the effectiveness and value for money of the Department of Defence’s acquisition of light protected vehicles. He did so on the grounds that the public disclosure of the relevant material would be contrary to the public interest because it would prejudice the security or defence of the Commonwealth and would unfairly prejudice the commercial interests of any body or person.

The Auditor-General is an officer of Parliament whose performance audit reports are prepared for the purpose of tabling and debate in Parliament and therefore attract parliamentary privilege. The information and analysis in these reports provide crucial support to the Parliament’s role of scrutinising the executive in relation to its spending of public moneys. The effect of the Attorney-General’s certificate was that the Joint Committee of Public Accounts and Audit reported that it was unable to inquire into the effectiveness and value for money of the Department of Defence’s procurement process.

Once the Attorney-General grants such a certificate, it triggers s 37(3), which provides that the Auditor-General is not permitted to disclose the relevant sensitive information to a House of Parliament or its Members or committees. But under s 37(5) the Auditor-General can still provide a full copy of the report, including the relevant sensitive information, to the Prime Minister, the Minister for Finance and any responsible Minister. The Auditor-General did so on 6 September 2018.

In November 2018, Senator Rex Patrick applied under the Freedom of Information Act 1982 (Cth) for a copy of the full report held by the Department of the Prime Minister and Cabinet. That application was refused and is the subject of legal proceedings before the Administrative Appeals Tribunal. Unsurprisingly, the Commonwealth claimed, among other grounds of exemption, that release of the full report would, or could reasonably be expected to, cause damage to the defence of the Commonwealth (s 33(a)(ii)) and that it would unreasonably affect the lawful business, commercial or financial affairs of an organisation (s 47G(1)(a)).

Greater controversy, however, surrounds the Commonwealth’s reliance on another ground of exemption – that release of the document would ‘infringe the privileges of the Parliament of the Commonwealth’ (s 46(c)). The reason the claimed parliamentary privilege exemption is important for this particular FOI application is that there is contention about whether the other grounds of exemption could withstand scrutiny. The Auditor-General, for example, took the view that the public disclosure of the redacted information would not unfairly prejudice the commercial interests of any body or person and that none of the information was the subject of a national security classification or otherwise damaging to Australia’s defence.

It appears that the Commonwealth’s underlying concern was that the Auditor-General’s report would prejudice the development of Australia’s ‘sovereign industrial capability’ to produce defence equipment in Australia, if it were shown that it did not provide value for money. Presumably, however, Parliament and its committees would be capable of taking into account the premium that could justifiably be paid for ensuring self-sufficiency in relation to defence procurement. Such a policy issue is one that would ordinarily be expected to be taken into account by Parliament in undertaking its scrutiny of government spending, rather than being excluded from its knowledge under a veil of secrecy.

But the most serious issue here is the attempt to use parliamentary privilege as a weapon to prevent Parliament from obtaining access to information and being able to debate it as part of its scrutiny of government policy and spending. The reasoning behind the reliance on this ground of exemption appears to be:

  1. that the Auditor-General’s report was prepared for the purposes of tabling in Parliament and protected by parliamentary privilege;
  2. that a certificate by the Attorney-General that prevented parts of that report from being tabled in Parliament is therefore incidental to the tabling of that privileged document and is itself privileged; and
  3. that if the full document were disclosed under the freedom of information application and then tabled in Parliament by the Senator who had applied for it, this would ‘impeach’ (by way of hindering or impairing the effectiveness of its operation) the Attorney-General’s certificate in breach of parliamentary privilege under article 9 of the Bill of Rights.

If such an argument were run in the United Kingdom, the Miller case suggests that the UK Supreme Court would give it short shrift. The Court might well observe that the Attorney-General’s certificate is not a decision of either House, but something imposed upon them from outside. It is not a form of parliamentary speech or voting that forms part of the core or essential business of Parliament and needs protection from the executive and the courts. Quite the contrary: it impedes Members from fulfilling their core business of holding the executive government to account and from speaking and voting upon the issue.

In Australia, the matter is a little more complicated because of the application of s 16 of the Parliamentary Privileges Act 1987 (Cth). This applies article 9 of the Bill of Rights, but defines ‘proceedings in Parliament’ as including:

all words spoken and acts done in the course of, or for purposes of or incidental to, the transacting of the business of a House or of a committee, and, without limiting the generality of the foregoing, includes:
(a) the giving of evidence before a House or a committee, and evidence so given;
(b) the presentation or submission of a document to a House or a committee;
(c) the preparation of a document for purposes of or incidental to the transacting of any such business; and
(d) the formulation, making or publication of a document, including a report, by or pursuant to an order of a House or a committee and the document so formulated, made or published.

On its face, it might be argued that the issuing of a certificate that prohibits a document being presented to a House is an act that is ‘incidental to’ the transacting of the business of a House, as it impedes or prevents it. But such a literal interpretation would be perverse. It would defy the purpose of parliamentary privilege, which is to protect the ability of Parliament to debate matters and hold the executive to account. Moreover, to argue that freedom of speech and debate in parliamentary proceedings is ‘impeached’ because an executive attempt to suppress such speech has failed, stretches the interpretation of article 9 well beyond its limits.

If the other claimed freedom of information exemptions with respect to defence and the damage to business are not made out, then the Attorney-General’s certificate, which depended upon the same exemptions (albeit in slightly different wording), would also most likely be invalid. For parliamentary privilege to be used in such circumstances to uphold the effectiveness of the certificate and prevent Parliament from being able to receive and debate the full report would be a travesty of justice.

Australian courts, in their analysis and application of parliamentary privilege, have paid close heed to its development in the United Kingdom and are likely to take a similar interpretative approach, which takes into account the history, context and purpose of parliamentary privilege. It is to be hoped that they will be as decisive as the UK Supreme Court in dismissing attempts to use parliamentary privilege to suppress freedom of speech in Parliament and prevent Parliament from fulfilling its role in ensuring ministerial accountability.

Anne Twomey is a Professor of Constitutional Law and Director of the Constitution Reform Unit at the University of Sydney.

Suggested citation:  Anne Twomey, ‘Can Parliamentary Privilege be Used to Shut-Down Parliamentary Accountability?’ on AUSPUBLAW (22 January 2020) <>