As Australia carries out its postal survey on same-sex marriage, the spectre of "transgender marriage" has been raised by some anti-LGBTI groups, as well as former Labor leader Mark Latham.



The Australian Family Association and the National Civic Council, which are very much opposed to same-sex marriage, have warned against allowing any two consenting adults to marry, claiming it will lead to changes in other laws.

Meanwhile, Latham wrote an opinion piece in The Daily Telegraph on Tuesday saying he supports marriage for straight and gay couples, but will vote "no" in a survey that would allow it for everyone.

So, will a "yes" vote in the postal survey allow all Australian couples to marry, or not? Here's some information:

The question you'll tick "yes" or "no" to in the postal survey later this year is: "Should the law be changed to allow same-sex couples to marry?"



But a "yes" vote won't automatically change the law — the parliament still needs to pass a bill to legalise same-sex marriage. And it's the wording of this bill that will determine who can and can't marry in Australia, not the postal survey itself.

On ABC TV's Q&A on Monday night, attorney-general George Brandis said there were several possible models for that bill — the "most high profile" being senator Dean Smith's, released ahead of the Liberal party room meeting that brought us the postal survey earlier this month.

Smith's bill, and the one released by Brandis in conjunction with the plebiscite legislation last year, both propose changing the Marriage Act in the same way: replacing the words "a man and a woman" with "two people".