The short answer

parliamentary privilege means

Parliamentary privilege consists of the rights, powers and immunities that allow the Australian Parliament and its members to carry out their functions without external interference. Its most significant element is the protection of free speech in parliamentary proceedings — anything said in Parliament cannot be questioned or impeached in any court or outside body. Privilege also includes the Parliament's power to punish contempts, to compel the attendance of witnesses and the production of documents, and to control its own internal proceedings. Privilege is not personal immunity for members of parliament; it is a functional protection for the institution of Parliament itself.

This is a federal system guide. State constitutions, parliaments and local-government laws can allocate comparable functions differently.

The useful question is not only “what is the rule?” but also “who administers it, which document controls it, and when might it change?” That distinction prevents an accurate general explanation from becoming wrong advice in a particular election, chamber or policy setting.

Evidence review

The core protection: freedom of speech in Parliament

Article 9 of the Bill of Rights 1689, which is incorporated into Australian law, provides that the freedom of speech and debates in Parliament must not be impeached or questioned in any court or place outside of Parliament. This means a member of parliament cannot be sued for defamation for anything they say during parliamentary proceedings, cannot be prosecuted for revealing state secrets in the chamber, and cannot be compelled to give evidence in court about what was said in Parliament.

The Parliamentary Privileges Act 1987 codifies and clarifies this protection for the Australian Parliament. Under section 16 of the Act, no evidence may be given in court of parliamentary proceedings for the purpose of drawing or inviting inferences about the proceedings themselves. This does not mean the words spoken in Parliament are secret — they are published in Hansard — but they cannot be used to attack the speaker in legal proceedings. A member who repeats a defamatory statement outside the chamber, however, loses the protection.

Evidence review

Contempt of Parliament: what it covers

Contempt of Parliament is conduct that obstructs or interferes with the work of the Parliament or its committees. It is not the same as contempt of court. Examples include refusing to answer a committee's questions without valid reason, threatening or intimidating a member of parliament in relation to their parliamentary duties, attempting to bribe a member, disclosing committee evidence before it is authorised for release, or obstructing a witness from appearing before a committee.

The Parliament has the power to investigate and punish contempts. It can summon the alleged offender, hold a hearing, and impose penalties including imprisonment for a defined period. In practice, the Parliament has rarely exercised its power to imprison — the last such case in the House of Representatives was in 1955. More commonly, the house or committee will resolve to admonish the person or report the matter to the relevant authorities. The power to punish contempt is a last resort and is used sparingly.

Evidence review

What privilege does not cover: limits and common misunderstandings

Parliamentary privilege does not give members of parliament immunity from the ordinary criminal law. A member can be arrested and charged with a criminal offence like any other person, although there are procedural requirements if the arrest occurs within the parliamentary precinct. Members are not immune from prosecution for fraud, assault, drug offences or any other crime committed outside parliamentary proceedings.

Privilege does not prevent a member from being sued for defamation for statements made outside the chamber — at a press conference, on social media, in a television interview or at a public meeting. The protection is strictly limited to parliamentary proceedings: speeches in the chamber, questions, committee hearings, and documents tabled or presented to the house. A member who waives privilege or repeats a protected statement outside Parliament puts themselves at legal risk.

Evidence review

Parliamentary committees and privilege

Parliamentary committees derive their powers from the houses that establish them, and their proceedings are protected by privilege to the same extent as chamber proceedings. Witnesses who give evidence to a committee are protected — their testimony cannot be used against them in court proceedings. However, this protection is not absolute. Under the Parliamentary Privileges Act, evidence given to a committee may be used in criminal proceedings for certain serious offences such as perjury or misleading the committee.

Committees have the power to compel witnesses to attend and produce documents by issuing a summons. Failure to comply with a committee summons without reasonable excuse is a contempt. This power is an important accountability mechanism — it allows Parliament to investigate government administration, corporate conduct and public policy independently of the executive and the courts.

Evidence review

Privilege and the courts: the interaction between parliamentary and judicial power

The relationship between parliamentary privilege and the courts is governed by the separation of powers. Courts cannot review the internal proceedings of Parliament — this is the exclusive cognisance of each house. However, courts can determine the scope and existence of privilege when it arises in litigation. If a party seeks to rely on parliamentary material in court, the court must determine whether doing so would breach privilege.

Under the Parliamentary Privileges Act, a court may admit evidence of parliamentary proceedings for certain purposes, such as proving that something was said, without drawing inferences about the proceedings themselves. This distinction can be subtle and is the subject of ongoing legal debate. The High Court has emphasised that privilege is not absolute and that courts must balance the public interest in parliamentary freedom against the public interest in the administration of justice.

Evidence review

State and territory parliamentary privilege

Each Australian state and territory parliament has its own parliamentary privilege, derived from its own constitution and legislation. While the principles are broadly similar to the Commonwealth privilege, the precise scope and limits can differ. For example, some state parliaments have enacted their own privileges legislation that may define contempt more broadly or narrowly than the Commonwealth Act.

State parliamentary privilege operates independently of Commonwealth privilege. A statement made in the New South Wales Parliament, for example, is protected from legal action in New South Wales courts but does not have the same protection if the proceedings are questioned in a federal context. The interaction between state and Commonwealth privilege is a complex area of constitutional law.

Common questions

Before you rely on the answer

Can an MP be sued for something they say on Twitter or Facebook under parliamentary privilege?

No. Parliamentary privilege only protects statements made during parliamentary proceedings — speeches in the chamber, committee hearings, and tabled documents. Statements made on social media, at press conferences, or in television interviews are not protected, even if the member is repeating something they also said in Parliament. If the statement is defamatory and published outside Parliament, the member can be sued.

What happens if a witness lies to a parliamentary committee?

Knowingly giving false or misleading evidence to a parliamentary committee is a serious contempt of Parliament and may also constitute a criminal offence. The committee may report the matter to the house, which can refer it to the relevant law enforcement authorities. The witness may also be charged with perjury or other criminal offences.

Can the media report on parliamentary proceedings without breaching privilege?

Yes. The media may report fairly and accurately on parliamentary proceedings under the protection of qualified privilege in defamation law. The Parliamentary Proceedings Broadcasting Act and standing orders regulate the broadcast of proceedings. A journalist who accurately reports what was said in Parliament is generally protected, but if they add their own defamatory commentary they may be exposed to liability.

Does parliamentary privilege apply to all parliamentary staff and contractors?

Parliamentary privilege primarily protects members of parliament and witnesses participating in proceedings, but it may also extend to parliamentary staff acting under the authority of a house or committee. The precise scope depends on the nature of the proceeding and the staff member's role. Administrative staff not directly involved in proceedings are generally not covered.

Source spine

Primary material used for this guide

Review trigger: Review when the Parliamentary Privileges Act 1987 is amended, when a significant High Court decision reinterprets the scope of privilege, or when the Parliament adopts new standing orders that change its exercise of privilege powers.

Archive note: Based on the Parliamentary Privileges Act 1987, Parliament of Australia practice and procedure documents, and Odgers' Australian Senate Practice as at July 2026. The scope of parliamentary privilege is defined by statute and evolving judicial interpretation.

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