Years of divisive public and political debate over same-sex marriage in Australia will come to a head on Wednesday when the results of the Turnbull government's postal survey are announced by the Australian Bureau of Statistics.
A diverse group of senators has moved swiftly to ensure legislation - authored by Liberal backbencher Dean Smith - will be debated as soon as Thursday, with the goal of legalising same-sex marriage by Christmas.
Alex Greenwich, the co-chair of the Equality Campaign, welcomed the bill as a "clear pathway" forward that could command the support of the Parliament. It was co-signed by Labor frontbencher Penny Wong, Liberal senators Linda Reynolds and Jane Hume, Greens senators Richard Di Natale and Janet Rice, and crossbenchers Derryn Hinch and Skye Kakoschke-Moore
"Just as our campaign has brought Australians together, senators are coming together to do something good and make people happy," Mr Greenwich said.
Prime Minister Malcolm Turnbull flew in to Australia overnight following a five-day series of leader meetings in south-east Asia. He is expected to address the public shortly after ABS head David Kalisch reveals the result during a media conference broadcast by all major television networks. Confident of victory, the 'yes' campaign has organised a series of major public gatherings in each capital cities, while the 'no' campaign will digest the results at the Intercontinental Hotel in Sydney.
A fierce parliamentary debate over religious exemptions is expected to follow the announcement. On Tuesday, Mr Turnbull slapped down his conservative colleagues by declaring Australians would not accept any watering down of existing anti-discrimination laws.
Mr Turnbull was responding to demands from some Liberals, led by Victorian senator James Paterson, that business owners should be able to refuse service for gay weddings based on religious or "conscientious" beliefs. That would involve overriding existing discrimination laws and creating special dispensation for people who held the "relevant belief" that homosexual relationships are unholy or immoral.
In remarks praised by his moderate Liberal allies as "strong", Mr Turnbull argued Australians would not support such moves - and neither would the Parliament.
"I don't believe Australians would welcome - and certainly the government would not countenance - making legal discrimination that is illegal, that is unlawful today," Mr Turnbull said.
Ideas of the kind Senator Paterson proposed "would have virtually no prospect of getting through the Parliament", Mr Turnbull added.
The Smith bill, or the rival legislation proposed by Senator Paterson, would be subject to a series of conscience votes on both sides, requiring a majority from the collective pool of Coalition, Labor and Greens MPs.
"People will be free to move whatever amendments they want and they will be debated and voted on," Mr Turnbull said. "They won't be ... constrained by any party policy."
A spokeswoman for the Coalition for Marriage said the Prime Minister's remarks were "surprising, given that he recently said that he believed more strongly in religious freedom than in same-sex marriage"
But Mr Turnbull was backed by senior ministers including the country's chief law officer, Attorney-General George Brandis, who rubbished the conservatives' proposals as "discrimination".
"We are certainly not going to remove one form of discrimination and at the same time instate another form of discrimination," Senator Brandis said.
"If you're a gay man or gay woman and you go into a florist and say, 'I'd like to buy a bunch of flowers', it's just wrong and illegal for the florist to say, 'I don't serve gay people' - just as it would be wrong or illegal for the florist to say to an Indigenous person, 'I don't serve Indigenous people'.
"If it's legally and morally wrong to discriminate against one gay person, I don't know how it becomes right to discriminate against two."
Government ministers instead backed the Smith bill, which legalises same-sex marriage while providing a moderate level of exemptions for religious organisations, and is backed by Labor, the Greens and others.
Senator Smith on Tuesday gave notice he would introduce the bill to the Senate on Thursday, presuming the "yes" vote succeeds.
MPs from all parties will be able to propose amendments to that bill, but crucially, there will be no cabinet or party room position dictating how people vote. All amendments would be subject to a free vote of Coalition, Labor and crossbench MPs.