What is parliamentary privilege?
A set of legal protections allowing members of a legislature to speak and act without fear of legal consequence for what they say in the chamber. It exists to protect the legislature's independence, not to give individuals personal advantage — though the distinction is frequently tested.
The two core elements:
Freedom of speech in proceedings. Anything said in the chamber or in committee cannot be the basis of a defamation claim or, generally, of any legal action. A member can name someone, make allegations, or reveal information that would otherwise be actionable.
Exclusive cognisance — the legislature regulates its own affairs and proceedings, and courts will not generally review what happens inside it.
Why it exists. It dates from struggles between parliaments and monarchs, where members were arrested and prosecuted for what they said. Without it, a government could suppress criticism through the courts, and a wealthy individual could deter scrutiny through the threat of litigation.
What it covers and does not:
Covered: speeches, questions, committee evidence, and documents laid before the house. Witnesses giving evidence to a committee are also protected, which is what makes parliamentary inquiries possible.
Not covered: press releases, interviews, social media posts, letters to constituents, and things repeated outside the chamber — a member who repeats a privileged allegation to journalists outside can be sued for that repetition.
Not a shield from criminal law generally. Privilege does not immunise members from prosecution for ordinary offences.
The contentious uses. Privilege has been used to reveal matters covered by court injunctions, to name individuals who could not otherwise be named, and to place information in the public domain. Defenders call this a necessary check on secrecy; critics call it circumventing a judicial decision without the safeguards a court applies. Both positions have force, and speakers generally discourage it.
Reporting is separately protected. Fair and accurate reports of proceedings carry qualified protection, which is why media can repeat what was said in the chamber when they could not otherwise.
General information; scope varies by jurisdiction.