What is parliamentary privilege?

The term "parliamentary privilege" refers to two aspects of the law relating to Parliament:

• the immunities of the proceedings of the Houses; and
• the powers of the Houses including the power to punish contempts.

These powers and immunities are fundamental to the operation of the Parliament because they protect the ability of the Houses, their committees and their members, to carry out their functions of inquiring, debating and legislating.

The most important immunity is the freedom of parliamentary debates and proceedings from question or impeachment in the courts. This means that members of Parliament cannot be sued or prosecuted for anything they say in debates. Similarly, witnesses cannot be sued or prosecuted for giving evidence to a parliamentary committee.

The principal powers of the Houses are:

• the power to inquire (including the power to compel witnesses to attend and give evidence, or to require the production of documents); and
• the power to determine and punish contempts.

A contempt is an action which improperly obstructs a House, a committee or its members in the performance of their duties. While the power to punish contempts is rarely exercised, it underpins the inquiry powers of the Houses and their capacity to prevent improper interference in their proceedings.

What is the legal framework?

Section 49 of the Constitution declared the powers, privileges and immunities of the Commonwealth Parliament to be the same as those of the House of Commons of the United Kingdom at the time the Commonwealth was established. The Constitution also provided that the Commonwealth Parliament could declare its own privileges if it chose to do so by way of legislation.

A significant declaration of the Commonwealth Parliament's privileges was made by the Parliamentary Privileges Act 1987. This Act declared some important privileges, abolished others and defined the penalties that a House may impose for contempt.

To supplement the Act, the Senate agreed in February 1988 to a series of resolutions – the "Privilege Resolutions", which establish:

• procedures to protect the rights of witnesses;
• procedures for the investigation of contempts; and
• criteria for determining matters relating to contempt.

The Senate Committee of Privileges, through inquiries into possible contempts, has established a body of precedents. The Committee has regard to these precedents, and the action taken by the Senate in relation to those matters, when considering whether particular conduct amounts to a contempt. Reports, and advices on privilege matters, may be found on the Committee's web pages.

Who and what is protected?

Parliamentary privilege protects those who participate in "proceedings in Parliament" from outside interference or legal action. The basic protection is provided by article 9 of the Bill of Rights 1689 which provides:

This protection is incorporated in Australian law by section 49 of the Constitution and section 16 of the Parliamentary Privileges Act 1987.

"Proceedings in Parliament" defined

Section 16 defines "proceedings in parliament" to include 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.

The definition specifically provides that this includes:

• the act of giving evidence to a House or committee
• the evidence given
• the presentation or submission of a document to a House or committee
• the preparation of a document for purposes of or incidental to the transacting of the business of a House or committee
• formulating, making or publishing a document by or pursuant to an order of a House or committee and
• the document formulated, made or published by or pursuant to such an order.

Examples

Examples of documents likely to be captured by this definition include:

• submissions to parliamentary committees
• draft questions to ministers (with or without notice)
• question time briefs or possible answers prepared by departments and agencies for their ministers and
• the briefs they prepare for their own appearances at Senate estimates.

Examples of documents or actions not likely to be covered include:

• the circulation of petitions (see the 11th report of the Committee of Privileges); and
• party or caucus meetings (including meetings of party or caucus committees).

Examples of documents formulated, made or published pursuant to an order of a House or committee include:

• business documents such as the Notice Paper, Senate Journals and the Parliamentary Debates (Hansard)
• answers to Senate questions on notice
• committee reports; and
• correspondence or documents authorised for publication by a committee.

The publication of Hansard attracts absolute privilege, but the publication of extracts, such as part of an individual senator's speech, does not. Publication of extracts by a senator to a journalist (for example) may attract qualified privilege, along with press reports of proceedings, or the use of extracts of speeches on senators' social media accounts. For qualified privilege, see chapter 2 of Odgers' Australian Senate Practice, under "Qualified privilege".

The question of whether communication from a constituent to a senator is protected by parliamentary privilege is a complex one which will hang on the particular facts. For example, an email seeking parliamentary action (eg to ask a question in an estimates hearing) may have a direct connection with parliamentary proceedings if the senator intends to, or does, use it to pursue that action. However, not all communication with parliamentarians has a connection to their parliamentary duties (for example it may relate to ministerial or party functions). For more information, see chapter 2 of Odgers' Australian Senate Practice, under "Provision of information to members".

What is contempt?

A contempt is any action which improperly obstructs a House or its members or committees in the performance of their duties. The power to punish contempts is the main power available to the Senate to protect the integrity of its processes.

The Privilege Resolutions set out procedures for the investigation of contempts and the criteria for determining matters relating to contempt. Resolution 6 sets out a non-exhaustive list of matters that may constitute contempts. Appendix 3 of Odgers' Australian Senate Practice has a summary of all the cases of possible contempt investigated by the Committee of Privileges.

Whether a person has committed a contempt is determined by a majority vote of the Senate, taken after at least 7 days' notice (privilege resolution 8) and usually on the recommendation of the Privileges Committee after an inquiry has been conducted.

Contempts by senators

Examples of contempts that may be committed by senators include:

• failure to comply with the resolutions of the Senate relating to the registration of senators'  interests or the registration of senators' qualifications under sections 44 and 45 of the Constitution;
• a member of a committee giving a copy of a confidential submission received by the committee to a Minister's office;
• asking for, obtaining or receiving a benefit in return for discharging the senator's duties under outside influence; and
• disobeying a lawful order of the Senate or a committee (for example, to appear before a committee or produce documents to the Senate).

Some of these matters are also covered by the criminal law (s.13, Parliamentary Privileges Act 1987; s.141.1, Criminal Code Act 1995).

Contempts against senators

Examples of contempts that may be committed by other persons in relation to senators include:

• obstruction of a senator in the exercise of his or her duties;
• improper influence of a senator; and
• molestation of a senator.

The threat of legal action against a senator to prevent him or her raising a particular matter in the Senate could also amount to a contempt.

Since the first such case of alleged intimidation of a senator was investigated by a select committee of privilege in 1904, the Senate has taken a fairly robust view as to whether senators have been improperly obstructed, on the basis that senators are robust, resilient and have a platform from which to argue their position. The greater emphasis has been on the protection of other persons, particularly witnesses before committees, and on the integrity of committee processes.

Other contempts

By far the most commonly investigated contempts involve conduct by, or in relation to, witnesses appearing before Senate committees. The following are possible contempts involving witnesses:

• a witness gives evidence to a committee that he or she knows to be false;
• a government agency punishes one of its officers for giving evidence to a committee that goes against the official agency line;
• a potential witness is given an inducement not to give evidence to a committee; or
• a witness is ordered to appear at a committee hearing and refuses to do so.

Penalties

In the worst cases, contempt may be punished by a term of imprisonment or the imposition of a fine. The Senate has never imposed such a penalty. Other penalties include admonishment or, in appropriate cases, the withdrawal of access to facilities at Parliament House (for example, a journalist may be excluded from the Press Gallery).

Matters of privilege

What is a matter of privilege?

A matter of privilege is a proposal to refer an action to the Committee of Privileges for investigation as a possible contempt. The key factor in determining whether a contempt has been committed is whether conduct improperly interfered with the ability of a House, a committee or a member to perform their functions (or had the potential to do so).

Raising matters of privilege

Standing order 81 sets out the procedure for raising matters of privilege in the Senate for investigation. The first step is for the senator who intends to raise the matter of privilege to write to the President of the Senate describing the matter.

The President is required to consider the matter against criteria which are also set out in the Privilege Resolutions (Resolution 4). In determining, as soon as practicable, whether to give precedence to a notice of motion to refer the matter to the Committee of Privileges, the President must consider:

• the principle that the Senate's power to adjudge and deal with contempts should be used only where it is necessary to provide reasonable protection for the Senate and its committees and for senators against improper acts tending substantially to obstruct them in the performance of their functions, and should not be used in respect of matters which appear to be of a trivial nature or unworthy of the attention of the Senate; and
• the existence of any remedy, other than that power, for any act which may be held to be a contempt.

The President's decision is conveyed to the senator and, in most cases, to the Senate. While the matter is under consideration by the President, the senator concerned must not take any other action in relation to the matter or refer to it in the Senate.

In most cases, the President decides that the matter should be given precedence though this is not an indication that the President necessarily considers that the matter warrants referral (just that the President considers that the jurisdictional criteria set by resolution 4 have been met). After this decision is notified to the Senate, the senator concerned gives a notice of motion to refer the matter to the Committee of Privileges for inquiry and report. The motion is usually dealt with as formal business (see Guide No. 8—Notices of motion) but, if debate is required, a matter of privilege is dealt with ahead of all other categories of business (see Guide No. 4—Categories of business). The question of whether the matter should be referred is then determined by the Senate.

If the President determines that a matter of privilege should not be given precedence, it remains open to the senator concerned to take further action; for example, by referring to the matter in debate or lodging a notice of a motion seeking to refer the matter to the Committee of Privileges. Again, it is for the majority of the Senate to decide if that action should be taken.

While only a senator may raise a matter of privilege (other than a right of reply or adverse reflection in committee evidence—see below), aggrieved persons may ask senators or committees to raise matters on their behalf.

The right of reply

Privilege Resolution 5 establishes a process for people who have been referred to in the Senate, in a way that adversely affects their reputation, to provide a response. The Senate was the first legislature to provide persons referred to in proceedings with a right of reply.

The right of reply allows a person who has been adversely affected by being named (or otherwise identified) in Senate proceedings to have a response incorporated in the parliamentary record. The person makes a submission to the President of the Senate requesting publication of a response. Provided the submission is not trivial or frivolous, the President refers it to the Committee of Privileges to consider.

The committee does not inquire into the truth or merits of the initial statement in the Senate or the response, but considers if the response meets the requirements of resolution 5. These include that it is succinct, strictly relevant and contains nothing offensive in character. If the committee is satisfied that a response should be published, it recommends to the Senate that the response be incorporated in Hansard. This means the response receives the same protection under parliamentary privilege as the original remarks.

The procedure does not apply to adverse comments made during Senate committee hearings but paragraphs (11) to (13) of privilege resolution 1 require committees to follow analogous procedures.

Senators and parliamentary privilege

This section sets out some other aspects of parliamentary privilege that may be of relevance to senators in the performance of their duties.

Freedom of speech

As noted above, the most significant immunity encompassed by the term "parliamentary privilege" is often referred to as freedom of speech in parliament: words uttered and acts done in parliament are not actionable in a court of law. For example, a person cannot take action for defamation against a member of parliament on the basis of words spoken in parliament.

However, the protection does not apply if a member of parliament repeats those words outside of parliamentary proceedings.

Effective repetition

There have also been cases where courts (perhaps erroneously) have allowed reference to be made to parliamentary statements for the purpose of defamation actions, to establish the meaning of statements made outside parliament. Members of parliament who have said words to the effect of "I stand by what I said in the chamber" or, "I do not resile from what I said in the chamber" have been sued for defamation on the basis that they have effectively repeated outside the parliament what was said inside (see the 134th report of the Committee of Privileges, Effective repetition).

The responsibilities of free speech

The Senate also agreed to a resolution in 1988 that enjoined senators to use their great power of freedom of speech responsibly, and to take into account:

• the damage that allegations made in parliament can do to the subject of the allegations and the institution of parliament;
• the limited opportunity available to persons other than members of parliament to respond to such allegations;
• the need for senators to have due regard to the rights of others; and
• the desirability of ensuring that any adverse reflections on a person are soundly based. This exhortation is contained in Privilege Resolution 9.

Interaction between privilege and other laws

Apart from the immunities conferred by parliamentary privilege on senators in the exercise of their duties, senators are subject to the ordinary law like any other person (see Guide No.22 – Provisions governing the conduct of senators).

Section 15 of the Parliamentary Privileges Act indicates that the police may exercise in the parliamentary precincts the powers which they possess under the ordinary law. Likewise, electorate offices are within the jurisdiction of the ordinary law. There are, however, a number of memorandums of understanding with investigative bodies which establish procedures to ensure the investigative powers of the police and other agencies are exercised in a manner that respects parliamentary privilege.

Similarly, senators have no general immunity from subpoenas, orders issued by courts or tribunals for the discovery of documents, or search warrants. However, the use before a court or tribunal of documents so obtained is constrained by the law of parliamentary privilege.

See chapter 2 of Odgers' Australian Senate Practice, under "Subpoenas, search warrants and members" for a discussion of the case law supporting an effective immunity from compulsory production of documents where the documents are so closely connected with proceedings in parliament that their production would involve unlawful questioning or impeaching of those proceedings.

Search warrants

In the only Australian case involving the execution of search warrants on a senator's offices (Crane v Gething, the court said that it did not have jurisdiction to determine whether parliamentary privilege prevented the seizure of documents by the police because the issue of search warrants is an executive act, not a judicial proceeding. The matter was returned to the Senate to determine whether the documents were protected by parliamentary privilege. The Senate did this by engaging an independent third party to assess the documents and determine which ones were covered by privilege (on the basis that all parties would accept the umpire's determination).

Subsequently, the Presiding Officers entered into a memorandum of understanding with the then Attorney-General and Minister for Justice, endorsing an Australian Federal Police Guideline on the execution of search warrants in members' and senators' offices.

The guidelines provide an opportunity for senators to claim parliamentary privilege over particular documents uncovered in the course of the search, and for such documents to be quarantined from the investigation pending a determination of the claim of parliamentary privilege.

Those arrangements were tested for the first time during a 2016 AFP investigation into a suspected leak from NBNCo. Three search warrants were executed, and numerous documents seized. Claims of privilege made by a senator and a member were referred to the privileges committees of their respective Houses. Each committee recommended that the claims be upheld, and each House resolved that seized material be returned to the parliamentarians making the claim (see the 163rd and 164th reports of the Senate Committee of Privileges and the report of the House Committee of Privileges and Members' Interests). A similar outcome was reached in another matter arising in 2018 (see the Senate Privileges Committee's 172nd and 174th report).

These agreed procedures are regularly reviewed and updated. The President of the Senate and Speaker of the House of Representatives tabled the most recent memorandum of understanding and associated AFP national guideline in 2024. There are equivalent agreements with the National AntiCorruption Commission and Independent Parliamentary Expenses Authority.

Need assistance?

Advice on any of the matters covered by this guide is available from the Clerk of the Senate on extension 3350 or clerk.sen@aph.gov.au. Specific advice on the operations of the Committee of Privileges is available from the Secretary on extension 3360 or priv.sen@aph.gov.au.

Last reviewed: June 2025