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Common(wealth) Knowledge #45: Referendum, plebiscite or postal survey?

Updated: Apr 7, 2023

The latest on the upcoming Voice to Parliament vote.

In the leadup to the referendum on the Indigenous Voice to Parliament that is set to be held later this year, there has been some confusion over the difference between a plebiscite and a referendum, with some people even suggesting that the 2017 same-sex marriage vote was a referendum. Some of this is thanks to coverage of the same-sex marriage vote that confused a postal survey with a plebiscite. To help clarify this, in this article we’ll go over four key indicators to determine whether something is a referendum, plebiscite, or postal survey.

This article will only cover the Australian context for referendums and plebiscites. In some foreign countries, the two are used interchangeably or are synonymous with one another. However, that is not the case here.

  1. What is being proposed?

The start of Section 128 of the Australian Constitution makes it clear that the only valid way to change the Constitution is by a referendum. This requires the proposal to pass both the House of Representatives and the Senate before being put to the Australian people. If the proposal involves any other aspect of Australian law, whether that be creating new legislation or amending existing laws, it will be a plebiscite or postal survey.

Some have suggested that the 2017 same-sex marriage postal survey was a “constitutional change to the Marriage Act 1961 (Cth).” This is completely inaccurate. The Commonwealth’s power to legislate with regard to marriage is found in Section 51(xxi) of the Constitution. If the vote was about changing the marriage power itself, for example extending the power to cover other forms of relationship, it would be a referendum. However, as the vote only involved changing the definition of ‘marriage,’ which is defined in the Marriage Act 1961 (Cth), not the Constitution, it was not a referendum.

2. Who votes first?

As mentioned earlier, for the Constitution to be changed via referendum, the proposal must first pass Parliament, before being put to the people. Only if the people also agree to it will it be given royal assent by the Governor-General and become law. In contrast, a plebiscite or postal survey will be put to the Australian people, before Parliament votes on it. Why it happens this way will become clear later.

3. Is it binding?

Because a referendum must pass Parliament first, it will be binding if it passes the double majority requirement for a referendum to pass a public vote. However, the same is not necessarily the case for plebiscites and postal surveys. This is where the distinction between the two becomes relevant.

Australia has only had two plebiscites in its history, although at the time both were referred to as ‘referendums.’ These were in 1916 and 1917, and both times were about whether Australia should adopt conscription. This was during the height of World War 1. Labor’s Billy Hughes came to power in 1915, and he supported implementing conscription to send soldiers overseas, in line with other Commonwealth nations, like New Zealand, Canada, and the United Kingdom. However, this issue divided the Labor Party.

In an effort to resolve the issue, Labor held two plebiscites to ask the Australian people whether they would support conscription. Both plebiscites failed, and led to Hughes and his supporters leaving the Australian Labor Party.

Australia’s first postal survey was in 1977, officially known as the National Song Poll, when Australians were asked what song they would like to become the next national anthem. This ballot paper was put to Australians as a multiple-choice question, where voters selected their favourite option.

The second postal survey was the 2017 same-sex marriage vote. Although this wasn’t a multiple-choice question, instead with a simple yes/no choice, like on the conscription plebiscite ballots, it is generally considered to be a postal survey because it wasn’t compulsory. Although the conscription votes weren’t compulsory either, it is generally accepted that if a plebiscite was to be held today, voting would be compulsory.

The evidence for this can be found in the same-sex marriage vote itself. Prior to the 2016 election, Malcolm Turnbull’s government proposed a plebiscite on the issue, where voting would be mandatory. However, after the election that year, the Turnbull government conceded to holding a non-compulsory vote, which was preferred by Labor and the crossbench. This is where the confusion between plebiscite and postal survey comes from.

The particular requirements for a plebiscite and postal surveys can be found in legislation passed by Parliament, as they are not provided for in the Constitution. They are primarily found in the Commonwealth Electoral Act 1918 (Cth), along with the requirements for voting at elections.

Despite the somewhat difficult distinction between plebiscites and postal surveys, it is clear that both options are not intended to be legally binding. They are held because politicians are uncertain about whether they should pass particular laws and amendments, so they put the vote to the public to decide. So, although not legally binding, they are binding in a political sense, because politicians are meant to represent the opinions and needs of their constituents, so should act in accordance with that. A plebiscite or postal survey makes the wishes of the voters clear on a particular topic, so politicians should act in accordance with that.

Only referendums are legally binding; however, the nature of Australia’s democratic system of government means that plebiscites and postal surveys will also be treated as politically binding. In all four instances of plebiscites and postal surveys, the will of the people was followed by the politicians. This is why Parliament votes after the people; they use the vote of the public to determine if they should pass the law in question.

4. What are the requirements for a majority?

The requirement for a majority in plebiscites and postal surveys is pretty straightforward: Do 50% of Australians, plus one, support one side? This is known as an absolute majority, where all that is needed is one more than half to succeed, the same system used for passing legislation in Parliament. The only exception to this is the National Song Poll, where the song with the most votes won, even if it wasn’t an absolute majority. This is known as a simple majority. Parliament can change between the two types of majority because the requirements for it aren’t contained in the Constitution, only in legislation passed by Parliament. However, absolute majorities are the most common.

In contrast, the Constitution states that a double majority is necessary for a referendum to succeed. This is a high bar to clear, which is why successful referendums are rare in Australia. For a referendum to get a double majority, the proposal must be voted for by a majority of Australians overall. This includes Australians in territories. The second majority is a majority of Australians in a majority of states. This means that a majority of people in at least four states must support it. This does not include territories. To put it more simply, a double majority is ‘a majority of Australians, and a majority of Australians in a majority of states.’ This is a safeguard put in place to make it difficult to undermine the Constitution.

In conclusion, there are four questions that should be asked to determine if a vote is a referendum. Is the proposal to change the Constitution? Does Parliament vote for it before the people do? Is it legally binding? Does it require a double majority? If the answer to all four questions is ‘yes,’ then it is a referendum, although generally, it isn’t necessary to answer more than just one of these questions before determining that it is a referendum.

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Elijah Granet’s ‘Better AustLII’ web extension.


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