AUDIO: KPMG Early Edition Correspondent Donna Demaio discusses the latest from Australia. 

Tony Abbott has slammed the brakes on the momentum towards same-sex marriage as two of his backbenchers prepare for a cross-party bill.

Liberal Warren Entsch will introduce marriage equality legislation to the parliament next month, pending a decision by the selection committee.

It will be co-sponsored by fellow Liberal Teresa Gambaro and seconded by Labor MP Terri Butler.

But the prime minister's reminded coalition MPs it's rare for private legislation to get up in the parliament, amid calls for him to allow them a free vote.

A government whip is toeing the leadership's line, saying MPs who think there'll be a vote on same-sex marriage anytime soon have "rocks in their head".

Andrew Nikolic has told the ABC anyone who thinks the issue should be prioritised over economic or national security issues is misreading the needs of the Australian people.