The High Court heard the ACT same-sex marriage case on Tuesday, December 3rd, reserving its decision until December 12. ACL’s Research Officer Daniel Simon attended the hearing and reports on the arguments presented.

The Commonwealth argued that the ACT’s same-sex marriage law, passed in October and taking effect on December 7, is invalid because it is inconsistent with the Commonwealth Marriage Act 1961. Under the Australian Constitution, the federal government has the power to legislate for marriage. The Constitution also says that any state or territory law inconsistent with a federal law is invalid.

In its arguments, the Commonwealth, represented by Solicitor-General Justin Gleeson SC, made two main points: the uniformity of marriage law in Australia, and the intention to define marriage as the union of a man and a woman.

One law for Australia

Firstly, marriage is a federal power because this allows for one uniform law throughout the country. Prior to 1900, the separate colonies had different laws governing marriage and divorce. A similar situation existed, and still exists today, in the United States. Wanting to avoid what they called this “mischief”, the founders deliberately gave the federal parliament the power to make laws for marriage, which they did with the 1961 Act.

In the words of Mr Gleeson, the need to avoid the problems of diverse marriage laws was “at the heart of the very case for Federation itself”.

The intention to define marriage as between a man and a woman

The second main theme in the Commonwealth’s arguments was that the Commonwealth has clearly shown its intention that marriage in Australia be limited to the union of a man and a woman. This was assumed in the original Act but made clear in the 2004 amendments, which inserted a definition and also expressly prohibited the recognition of same-sex relationships formalised overseas.

In response, the ACT argued that the Commonwealth law only regulates opposite-sex relationships, and that it is open to the states to confer the status of “marriage” onto same-sex couples. The ACT also argued that although the intention was clear, the text of the Marriage Act as amended does not expressly prohibited the formalising of same-sex marriages in Australia.

The High Court also allowed submissions from Australian Marriage Equality (AME), represented by Mr Kirk SC, who argued that the ACT law creates a new and distinct status, not “marriage” but “same-sex marriage”. The ACT – and any state or territory – has the right to do this, they argued, because the federal law only deals with the status “marriage” as defined in the Act.

The potential for other statuses of marriage

The Court drew two important points out of the ACT and AME arguments.

Firstly, after some probing questions from Chief Justice French and Justice Bell, AME had to admit that, based on its argument, a state or territory could legislate a new status of marriage for any type of relationship, including those currently prohibited by the federal Marriage Act. Such relationships include those where one or both parties are a child, or already married to somebody else, or where true consent is not given, or where the parties are related.

The fallacy of “equality”

Secondly, it was exposed just how shallow the claim of “equality” is.

Justice Bell asked the ACT’s solicitor Ms Eastman SC whether a same-sex couple married in the ACT would be “married” for the purposes of any Commonwealth laws which deal with married couples – such as the Evidence Act, which allows a person not to be compelled to give evidence against their spouse in a criminal matter.

Ms Eastman replied that “for Commonwealth laws, they are not recognised as married”.

In the words of Justice Bell, the ACT Act gives “a somewhat limited quality to equality”.


It is not known how the Court will rule next Thursday. It may decide the ACT Act is totally invalid, totally valid, or something in between. Despite the uncertainty, some same-sex couples are planning to wed under the new law on the weekend, even though they may be left without the legal recognition they thought they gained.

Based on legal advice the ACL has received, it seems there are strong grounds for the Court to reject the ACT bill as unconstitutional.

There is a clear case for the importance of a single marriage law for the whole of Australia. Moreover, it was the clear intention of our elected federal parliament to define marriage in Australia as between a man and a woman.

The transcript of the hearing is available here.

An audio-visual recording is available here.

The submissions from each party are available here.


  • The case was heard before the full bench of the High Court, with the exception of Justice Gageler, who was recused, most likely because of an advice he gave as a private lawyer to the ACT Government regarding their civil union laws in 2006.

  • The Commonwealth Government's arguments were presented by Commonwealth Solicitor-General Mr Justin Gleeson SC.

  • The ACT Government's arguments were presented by ACT Solicitor-General Mr Paul Garrisson SC and Ms Kate Eastman SC.

  • AME was allowed by the Court to make oral and written submissions as an amicus curiae, or “friend of the court” – a party not connected with the case but with arguments which may assist the Court with their decision. They were represented by Mr Jeremy Kirk SC.