top of page

Common(wealth) Knowledge #16: What are Constitutional Conventions?

Updated: Apr 7, 2023

This week's article was chosen by our followers on Twitter.

Constitutional conventions play a major role in constitutional law in Australia, yet they are often misunderstood or hard to explain. So it’s no wonder that when we put out a poll to our audience on Twitter on the topic to cover in Common(wealth) Knowledge #16, it was picked as the winner. So in this edition of Common(wealth) Knowledge, we will look at what they are, why we have them, and how they operate, along with some real-world examples of their successes and failures.

Constitutional conventions are often said to be the unwritten laws of the Australian Constitution. As we will see, these conventions can be written down, but they are ‘unwritten’ in the sense that they are not expressly written into the Constitution. These constitutional conventions are not to be confused with the pre-Federation conventions in the United States and Australia, where their respective founders wrote their respective constitutions.

The notion of unwritten constitutional provisions may seem odd to many Australians, as we have a written Constitution, like the United States. These conventions originated in the United Kingdom, where there is an ‘unwritten constitution.’ While various laws, like the Magna Carta and Bill of Rights 1689, are considered to be ‘constitutional documents,’ they only make up part of the UK’s constitution. The rest of it is found in convention and the common law of the courts. This tradition was passed down to Australia as a result of colonisation.

Constitutional conventions exist to uphold constitutional principles. These principles include the rule of law, separation of powers, and responsible government. As mentioned in Common(wealth) Knowledge #14 in relation to the separation of powers, these principles are found in legislation, and especially in the Constitution itself. Judges often conclude that these are implicit principles; they are found by reading between the lines. For example, because Sections 1, 61, and 71 grant the legislative, executive, and judicial branches of the government express authority over their respective branches, the High Court of Australia concluded that there was an implicit separation of powers.

Generally, constitutional conventions exist to regulate the Crown, in Australia represented by the Governor-General, and the Executive. The Constitution has 60 sections about Parliament, whereas it only has 10 about the Executive. Again, this is largely due to the evolving relationship and power balance between the Crown and the Executive. In fact, the Prime Minister and Cabinet aren’t even mentioned in the Constitution, so their very existence is the result of a constitutional convention.

There are two ways to create constitutional conventions, by custom/precedent or by agreement. Often agreements are made to formally recognise customary practices. One constitutional convention made by agreement, not custom, that we have seen before is the Balfour Declaration of 1926. Leaders of the Commonwealth Dominions, including Australia, and the United Kingdom met and agreed that they would be equals in the Commonwealth of Nations. The UK previously had the power to dictate the foreign policy of the Dominions and pass laws over them without their government’s consent. However, in the Balfour Declaration the UK agreed that it wouldn’t exercise this power. Canada, the Irish Free State, and South Africa still wanted a legally-binding agreement, so the Statute of Westminster was created. When the Dominions adopted the Statute of Westminster 1931 (Imp) by passing it, as Australia did with the Statute of Westminster Adoption Act 1942 (Cth), the Balfour Declaration had transitioned from a constitutional convention to a binding statute.

The other, more common, way that a constitutional convention is formed is through precedent. This is what we really mean when we talk about an ‘unwritten constitution,’ because conventions formed by agreement are still written down. Sir Ivor Jennings, a leading authority on British constitutional law, described the questions that must be asked to determine if a practice has become a convention by precedent:

“[F]irst, what are the precedents; secondly, did the actors in the precedents believe that they were bound by a rule; and thirdly, is there a reason for the rule? A single precedent with such a reason will be of no avail, unless it is perfectly certain that the persons concerned regarded them as bound by it.”

Although it is difficult to compile a complete list of all conventions, these are some of the most important ones, and apply at both levels of government:

  1. The Crown (through the Governor-General or State Governor) will appoint the person most likely to have the backing of a majority of MPs in the lower House of Parliament as the Prime Minister (or Premier).

  2. The Governor-General will appoint and dismiss ministers on the advice of the Prime Minister.

  3. The Governor-General will be appointed by the Crown on the advice of the Prime Minister and Cabinet.

  4. The Attorney-General will nominate potential judges to Cabinet for review, and the Prime Minister will advise the Governor-General of Cabinet’s decision. The Governor-General will then appoint the judge.

  5. The Prime Minister and Cabinet, especially senior ministers, will advise the Governor-General on when Parliament should sit. In accordance with Section 5 of the Constitution, the Governor-General will then set the timetable on this advice. However, the Governor-General can go against the advice of a Prime Minister who delays the sitting of Parliament because they are not sure if they have the confidence of a majority of the lower House.

  6. The Prime Minister shall advise the Governor-General on when to dismiss Parliament, provided that it is within the three-year period defined by Section 28 of the Constitution.

  7. The Governor-General, or the monarch themself when relevant, will assent to all bills.

Many of these conventions were tested by Governor-General John Kerr’s dismissal of Prime Minister Gough Whitlam. There is still an ongoing debate as to whether Kerr should have dismissed Whitlam. The biggest constitutional issue is whether the situation allowed the Governor-General to exercise his prerogative powers (discretionary powers of the Crown) and dismiss a sitting Prime Minister. However, that is a debate for another article.

Another convention involved in the Whitlam Dismissal was the first convention from the list. Malcolm Fraser was appointed as Whitlam’s replacement because he could guarantee that appropriation bills, necessary for the government to spend money, would pass the Senate. However, convention dictates that this convention only applies to the House of Representatives. It is why Section 53 of the Constitution only allows the Senate to pass or reject appropriation bills. But it could be argued that this led to a new convention, as both the Liberal/Country Party and the Labor Party agreed that they wouldn’t use the Senate to block appropriation bills for the purpose of forcing the Governor-General to pick a new Prime Minister.

More recently, the revelation that former Prime Minister Scott Morrison had secretly been appointed to several ministries tested the conventions again. Here, Governor-General David Hurley followed convention by appointing ministers on the advice of the Prime Minister. It is also unclear whether Hurley knew that Cabinet had not endorsed this decision, which is usually the norm.

Constitutional conventions provide a degree of flexibility not attainable under a written constitution, as their applicability depends on the specific circumstances of the situation. According to Professor Anne Twomey:

“The point of relying on conventions and eschewing rigid rules is to achieve the flexibility that ensures the Constitution of capable of adapting to changed conditions, rather than snapping and breaking under strict rules that are unenforceable.”

This is important in a system that has developed over many centuries. However, the trade-off is that constitutional conventions aren’t actually laws. They rely on all parties acting in good faith and for the benefit of all; they are not legally binding. Constitutional conventions are political, not legal, in nature. Part of this is because the separation of powers grants parliamentary privilege to politicians, preventing their actions in Parliament from being taken to court. This comes to us from the Bill of Rights 1689, where Article 9 says:

“[T]he freedom of speech and debates or proceedings in Parliament ought not to be impeached or questioned in any Court or place out of Parliament.”

This is now found in Section 49 of the Constitution. Thus, in R (Miller) v Secretary of State for Exiting the European Union [2017], [146], the UK Supreme Court said that “[j]udges therefore are neither the parents nor the guardians of political conventions; they are merely observers.”

Constitutional conventions, while often poorly explained, should not be, and so I hope that this article provides some clarity about conventions, both in theory and in practice.

Stuart Jeffery is a freelance researcher & digital editor for 6 News. His views on personal social media pages are his & his only, and do not reflect the views of 6 News or our journalists. He abides by 6 News' editorial standards relating to fairness & accuracy. Sign up to our new free newsletter to catch up on all our original reporting you may have missed & to read the latest from the editor - click here. Help support unbiased journalism & keep us independent: donate just $4 a month on Patreon & receive exclusive benefits. Want to inform others? Share the link to this story on social media & with your family & friends using the buttons below.



Anne Twomey, The Veiled Sceptre: Heads of State in Westminster Systems (Cambridge University Press, 2018).


bottom of page