With the second rejection of a bill to hold a plebiscite on legalising same-sex marriage, the government now moves to Plan B: a $122 million postal vote.
Enrolled voters can expect to receive papers from the Australian Bureau of Statistics (ABS) within six weeks.
Opponents of the move, including Tasmanian independent MP Andrew Wilkie, have already announced they will lodge a High Court challenge within the coming days.
Same-sex rights advocate Rodney Croome (kroom) says legal advice from barrister Ron Merkel has raised questions over the vote's legitimacy.
"The problem of the government exceeding its executive authority continues to be an issue with this new proposal. Mr Merkel also feels that the idea of a postal vote running through the ABS may exceed the ABS's authority, particularly when we consider whether a postal vote on marriage equality is actually statistic gathering or not."
The union representing ABS staff says their members are worried the vote could politicise the independent agency, and are concerned about work and capacity constraints.
Associate Professor of Politics at Flinders University, Dr Haydon Manning, says by charging the ABS with running the vote, the government can avoid several hurdles, such as getting legislation through parliament.
He says a postal plebiscite is the only option left for Malcolm Turnbull.
"Malcolm Turnbull does not have the numbers in his partyroom, let alone with his Coalition partners the National party, to do anything other than cobble together some sort of indicative vote, and that's all this is, as flawed as it is. However, if it's a reasonable sample and it's a 'yes' vote, then the door is open for a vote in the parliament in early December, and for the Prime Minister to put this issue away."
With voluntary participation and a rushed turnaround, as well as its non-binding status, some analysts have questioned the ballot's legitimacy.
Voters whose details have changed, or who are overseas, could miss out on having their say.
Labor Senator Penny Wong has derided the renewed attempt to hold a plebiscite as "an expensive stunt".
Ms Wong, who is in a same-sex relationship, has told the Senate the government is trying to shirk responsibility for deciding the issue.
"We are elected to come here to vote, to make decisions. This country didn't have a plebiscite or a postal ballot on the Race Discrimination Act, the Sex Discrimination Act, native title legislation, scrapping of the White Australia policy, whether women should get equal pay, I don't think Tony Abbott took to a people's vote cutting billions of dollars out of health and education. I don't think the government took to a people's vote whether or not corporations should get a big tax cut, but on this they want us to say, 'we handball it to the community'."
Labor has not confirmed if it will campaign for the 'yes' vote.
Flinders University's Dr Manning says the federal Opposition might decide to boycott it altogether.
"If they can really muddy this postal vote, really delegitimise it, they are then able to carry into the next election this issue as their issue, then that's a political advantage. But if you're gay and you want to see this happen, would you be betting on Labor necessarily winning the next election, and then being able to legislate it?"
Should the majority of the votes be 'yes', the government has promised to introduce a private bill for a free vote in the final sitting fortnight of the parliamentary year.
Malcolm Turnbull says it's the fairest way to judge the will of the Australian people.
"We put our faith in them, we will give every Australian a say on this issue, as we promised them in the election. The Labor Party could have voted today to enable there to be a compulsory attendance ballot, they have refused to do that, because they don't trust the Australian people. We will give everyone a vote."
The result of the postal vote is expected be declared on November 15.
