After the Senate's second rejection of a bill to hold a plebiscite on legalising same-sex marriage, focus turned to the government's back-up plan - a $122 million postal vote.
The Australian Bureau of Statistics is set to begin distributing ballot papers in the mail from September 12, which voters will have to complete and return by November 7.
Australians have two weeks to either enrol to vote or update their details via the Australian Electoral Commission website.
The final poll result is planned for November 15.
But a challenge to the legality of the postal poll has begun.
Lawyers acting on behalf of independent MP Andrew Wilkie, Parents and Friends of Lesbians and Gays, and lesbian parent Felicity Marlowe have lodged a challenge in the High Court.
Public Interest Advocacy Centre CEO Jonathon Hunyor says the challenge rests on a few key points.
"Firstly we'll be arguing that the Finance Minister lacks the power to approve the funding in this case because there is no real urgency. Secondly, that the legislation gives the Finance Minister the power to make these sorts of allocation of funds without parliamentary authorisation is itself invalid. Thirdly, that the exercise simply isn't a statistical one and so it doesn't fall within the powers of the ABS."
Yet there's hostility towards other elements of the plebiscite, too, with some - including supporters of marriage equality - planning to opt out of the plebiscite altogether in defiance of the postal process.
Former High Court justice Michael Kirby is one of them.
He told Sky News no other rights issue in Australia has ever been put to a public survey, and the planned postal vote makes him feel like a second-class citizen.
"It's a very wrong thing and very hurtful that there people with hate in their eyes and with animosity in their actions and cruelty in their attitude to young people who are bullied and humiliated, it ought not to be happening in Australia and we ought to join the rest of the countries of a similar kind in the world and provide equality of civil rights in a secular parliament, voted on in accordance with the constitution."
However, Queensland Liberal MP Andrew Laming has attacked those considering a boycott.
"For Australians to see that kind of conduct, a spit in the eye from the yes campaign is incredibly disappointing. I will be urging Australians to vote however you feel on this issue, but not to boycott a plebiscite. If you find opening an envelope, filling out a form, putting a mark on it, sealing the envelope and posting it back as offensive, then I question whether you fully understand how democracy works."
The proposed postal vote would be non-binding and non-compulsory, leading many to question its validity.
Some Australians living overseas during the voting period could potentially miss out, too.
Trent Zimmerman was among Liberal MPs who forced the issue this week by trying to get the government to simply bring on a free vote in parliament.
He says those who want the change must seize this opportunity.
"Whilst not my first choice, it will allow this issue to be resolved once and for all by Christmas this year. If you believe that the government should not be able to tell you who you can and can't marry, then vote yes. If you want to help bring this country together so we can all move on from this issue, then vote yes."
The government has promised to introduce a private bill for a free vote in the final sitting fortnight of the parliamentary year if most voters return a yes vote.
Malcolm Turnbull has definitively ruled out any other process.
"Our policy is very clear. We will not facilitate the introduction of a private members' bill on this matter unless the Australian people have given their support."
