Numbers exist for Lib same-sex vote: MP

Assistant treasurer Josh Frydenberg believes the numbers exist in the Liberal party room for a conscience vote on gay marriage.

Appearing on ABC TV's Q&A program, Mr Frydenberg said recognising gay marriage was inevitable in Australia.

"I am hoping we have a conscience vote," he said.

Host Tony Jones asked if he thought the numbers were there in the party room for a conscience vote.

"Well, I think they are," Mr Frydenberg said.

He said he believed a gay marriage vote would happen this year, but the views on both sides of parliament need to be respected.

"Yes, I think it will, yes, I do," he said.

"Dare I say it, it's Bill Shorten's bill that he introduced today, but it's not Bill Shorten's issue, and that's why it's really important that it is a cross-party agreement."