A cross-party bill to allow same-sex marriage will be introduced and debated in parliament on Monday.

Parliament's selections committee, which determines which private member's business is debated, tonight approved the legislation for introduction.

The bill will be moved by Liberal MP Warren Entsch and supported by Labor, the Greens and independents.

.@terrimbutler co sponsor #marriage equality bill confirms Parl Selection Committee met bill be introduced Monday pic.twitter.com/8igcirsNLu — Catherine McGrath (@catherine_h_mcg) August 11, 2015

Mr Entsch, who has Labor, Green and independent support for his bill, declined to reveal the details of the bill until he introduces it.

Co-sponsor, Labor MP Terri Butler, said it would change the definition of marriage from a man and a woman to "two people".

She said the bill would make it clear that church ministers, pastors and chaplains would not be compelled to preside at same-sex marriage services.

Mr Abbott used parliament to take a shot at the Labor national conference's decision to lock all caucus members into voting for same-sex marriage, rather than have a conscience vote, if it is not enacted by the time of the election after next.

"Members' opposite consciences appear to have a use-by date on them," Mr Abbott said.