In the English-speaking world, members of parliament have the right to speak freely in parliament without risking arrest or being sued. The Queen, ministers, governments and officials can all be criticised and corruption exposed. Known as parliamentary privilege, it is a vital aspect of parliamentary democracy.
It was not always so. Until the latter part of the seventeenth century the king of England believed his authority was derived from God. Opponents and critics (including members of parliament) could be imprisoned, property seized, wars declared and taxes imposed whenever he chose. Parliament was seen as little more than a rambunctious hindrance.
This led to significant conflict, including the English Civil War (1642 to 1651) between King Charles I and Parliament. The stakes were high - Charles lost and was executed, and England became a republic for 19 years. When the monarchy was restored, Charles II promised to rule in cooperation with Parliament.
However, he failed to do so, and Parliament grew increasingly unhappy with his wars and religious policies. In 1681 he dissolved Parliament and ruled alone until his death in 1685. Things got even worse when his brother, James II, succeeded him. That prompted the so-called Glorious Revolution of 1688, when James was forced into exile and replaced by his nephew William of Orange, and Mary, Charles' daughter.
The invitation to William and Mary to take the crown was conditional on them agreeing to the Declaration of Rights, which became the 1688 Bill of Rights.
The Bill of Rights is now regarded as one of the fundamental pillars of English law. It has also had a considerable impact elsewhere – it was used as a model for the US Bill of Rights in 1789, for example, and its influence can be seen in other rights-based documents such as the United Nations Declaration of Human Rights and the European Convention on Human Rights.
The Bill firmly established the principles of frequent parliaments, free elections, no right of taxation without Parliament's agreement, freedom from government interference, the right of petition, and just treatment of people by courts. It also established parliamentary privilege: Article 9 states: "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 main principles of the Bill of Rights remain in force today, although most have long been incorporated into legislation. They are also periodically cited in legal cases, both in England and the countries that inherited English law. The chief exception is parliamentary privilege, which in many jurisdictions continues to rely on the Bill of Rights.
This is true of Australian state parliaments. However, the Commonwealth parliament has gone further and incorporated the parliamentary privilege provisions of the Bill of Rights into legislation - the Parliamentary Privileges Act 1987. Section 16 of this states:
Parliamentary privilege in court proceedings
(1) For the avoidance of doubt, it is hereby declared and enacted that the provisions of article 9 of the Bill of Rights, 1688 apply in relation to the Parliament of the Commonwealth and, as so applying, are to be taken to have, in addition to any other operation, the effect of the subsequent provisions of this section.
(3) In proceedings in any court or tribunal, it is not lawful for evidence to be tendered or received, questions asked or statements, submissions or comments made, concerning proceedings in Parliament, by way of, or for the purpose of:
(a) questioning or relying on the truth, motive, intention or good faith of anything forming part of those proceedings in Parliament;
(b) otherwise questioning or establishing the credibility, motive, intention or good faith of any person; or
(c) drawing, or inviting the drawing of, inferences or conclusions wholly or partly from anything forming part of those proceedings in Parliament.
Entrenching an article of the Bill of Rights in specific legislation is often intended to protect it from judicial amendment. Courts are notorious for interpreting legislation to limit its application or find meanings that were never intended, then using those interpretations as precedents in subsequent cases. Over more than three hundred years, this has occurred many times to the Bill of Rights.
Despite both parliament and the courts being adversarial, judges can sometimes conclude that the rowdy and undignified nature of parliament makes it less competent to decide what the law should be. That is what King Charles I thought in the 17th century.