Immunities of the houses
The principal parliamentary immunity is the immunity from civil or criminal action, and examination in legal proceedings, of members of the houses and of witnesses and others taking part in proceedings in Parliament. This immunity is known as the right of freedom of speech in Parliament, because it has the effect of ensuring that members, witnesses and others cannot be sued or prosecuted for anything they say or do in the course of parliamentary proceedings. This freedom of speech has always been regarded as essential to allow the houses to debate and inquire into matters without fear of interference.
Freedom of speech was codified in the Parliamentary Privileges Act 1987 (hereafter the 1987 Act). The Act declares the scope of freedom of speech in parliamentary proceedings. ‘Proceedings’ are defined in subsection 16(2) of the Act as:
... 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.
The meaning of ‘impeached or questioned’ is also defined. It is not lawful in any court or tribunal to question the truth, motive, good faith, or intention of any person by reference to parliamentary proceedings, or to draw any inferences or conclusions from those proceedings.
This does not prevent the use of proceedings of Parliament in court to establish a material fact, for example, to prove that a person was at a particular place at a particular time, to test the fairness and accuracy of a press report of parliamentary proceedings, or to prosecute certain offences against Parliament.