Prime minister Malcolm Turnbull has introduced a bill for a same-sex marriage plebiscite to the parliament, 13 months after the controversial vote was first conceived under Tony Abbott.
Turnbull told the chamber that the Coalition was putting its faith in the Australian people by asking them about same-sex marriage.
"We know that their answer, whether it is yes or no, will be the right answer because this is an institution thousands of years old that we are talking now about making a fundamental change to," he said.
"If ever there is an issue to be put to a plebiscite, this is one that can be, and should be, because it is a very straightforward question."
Liberal MPs slowly rolled in to the chamber from the beginning of Turnbull's speech, with the benches behind him near-full as he hit his stride.
Tony Abbott, under whom the plebiscite proposal was formulated, was in the chamber for the vote.
The opposition benches were more sparsely populated, with acting leader Tanya Plibersek, shadow attorney general Mark Dreyfus, spokesperson for equality Terri Butler, and a few others present.
Turnbull hit out at Labor leader Bill Shorten, who is planning to advise Labor caucus to oppose the bill.
"We have a mandate for [the plebiscite] and the opposition should respect it," he said.
Turnbull also criticised the rhetoric around the plebiscite, saying it is "utterly wrong" and "dreadful leadership" to characterise people who do not support a parliamentary vote on same-sex marriage as homophobic or "hating homosexuals".
"We have to respect there are sincerely held views on this issue. They are often informed by deeply felt conscience, by religious commitment, by faith," he said.
Turnbull also spoke on his own support for same-sex marriage.
"I support same-sex marriage not despite being a conservative, but because of it. Because we value commitment," he said.
There was a faint "hear, hear" from the government benches as Turnbull said "our society would be stronger if more people were married and there were fewer divorces".
Turnbull told the chamber that February 11 is the "soonest practicable date" the plebiscite can be held, and that the question it will put is fair.
"This is a simple question that does not presuppose any point of view."