A Liberal senator would be surprised if same-sex marriage is not legislated before Christmas as a new poll shows majority support for the 'Yes' vote.
The Guardian-Essential poll of nearly 2000 people found that six in 10 people have voted 'yes' in the postal survey, slightly down from a poll three weeks ago.
"I'm a yes voter and I hope that is how it will happen. I'd be surprised if it didn't," Senator James Paterson told reporters in Canberra on Tuesday.
"I don't think anyone wants to leave parliament this year without having dealt with this issue one way or another - particularly if there's a 'yes' vote."
The poll also found 34 per cent of participants had voted 'no' - up by four per cent.
Meanwhile, nine in 10 Australians over 55 have voted compared with only three in five people aged under 35.
Senator Paterson says any bill legalising same-sex marriage should not be rushed through parliament.
A bill proposed by Liberal senator Dean Smith was a good start, he said.
"But I think there are other alternatives that go further in protecting religious liberty and freedom of conscience."