Prime Minister Tony Abbott is under pressure to allow a free vote within the Liberal Party on gay marriage by the end of the year.
Mr Abbott has declined to allow his frontbench a free vote on same-sex marriage, leading to the defeat of legislation in 2012.
However, the success of a referendum in Ireland to amend its constitution on the issue has led to calls for another parliamentary debate.
Assistant Education Minister Simon Birmingham said the Irish referendum was another sign to Australia there was strong public support in Western countries for gay marriage.
"When it is the right time ... one of us will make sure that it is raised," Senator Birmingham said of the Liberal party room.
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Liberal backbencher Wyatt Roy said he expected the issue to be raised in the party room by the end of the year.
"We could very easily have a discussion about legislation in the party room and we could have a vote in the parliament before the next election," Mr Roy told ABC radio on Monday.
Mr Roy said he feared that if the issue dragged out into an election year it would become a political football.
"My preference is that issues like this are not turned into political footballs and it would be easier, I think, politically and better for the country if we were to deal with it this year rather than in an election year," Mr Roy said.
Mr Abbott's lesbian sister said she hoped her brother allowed his MPs a conscience vote.
"I'd like something more from the current prime minister, who happens to be my brother," Christine Forster told Sky News.
