That could trigger a long-awaited debate taking place in the Coalition party room on whether MPs should be granted a free vote on the issue and then, possibly, a vote as soon as August. Gay marriage advocate and Liberal MP Warren Entsch. Credit:Andrew Meares "Just today I spoke to two Labor Party people who offered to co-sponsor a bill," Mr Entsch said. "This has to be owned by all parties...this doesn't need one individual's brand on it, it needs respect and sensitivity." Mr Perrett confirmed he was one of the Labor MPs prepared to work with Mr Entsch on the issue, however, he said he hoped, in the first instance, that the bill brought forward by Mr Shorten and deputy Labor leader Tanya Plibersek was passed by the Parliament.

"The boss has something before the House now. Let's see how that goes, if the [Liberal senator] Simon Birmingham and Warren can win the party room over," he said, adding that if the bill failed, he was willing to work with Mr Entsch and co-sponsor a bill. Labor MP Graham Perrett (pictured with leader Bill Shorten) has spoken to Liberal and Greens MPs about prospect of a cross-party same-sex marriage bill but appears to have cooled on the idea. Credit:Renee Melides "It's certainly time, if the conservative Poms and Kiwis, and now the Irish have beaten us to it, it's starting to get embarrassing. I'm proud of Tanya and Bill for bringing it on but most importantly we have to get this done." Asked directly if he was willing to co-sponsor a bill with Mr Entsch, Mr Perrett said, "Warren and I work very well together in the Friends of LGBTI [lesbian, gay, bisexual, transgender and intersex people] and that's just my position." Mr Perrett added that "committed, monogamous relationships are the best thing in the world, we should be doing all we can to make sure the Parliament allows more of them".

Mr Shorten conceded on Thursday the issue had to be handled in a bipartisan fashion, though he maintained pressure on Prime Minister Tony Abbott to allow his MPs a conscience vote on the issue, declaring Australians would be "shocked" if a free vote was denied Liberal MPs. Mr Shorten said he hoped the matter could be bipartisan because "it is the only way it can succeed. Tony Abbott's right in that but the only way that it can succeed is if Tony Abbott allows a free vote. That is the question which is before the Parliament." The Labor leader will press ahead and present his same-sex marriage bill to the Parliament next Monday, though that bill is unlikely to force a vote on the issue. On Wednesday Mr Abbott set out the conditions for a conscience vote for Liberal MPs on same-sex marriage, declaring that "if our Parliament were to make a big decision on a matter such as this, I want it to be owned by the Parliament, and not by any particular party". Cabinet ministers have told Fairfax Media they believe it is almost inconceivable that the Prime Minister will not, eventually, grant a conscience vote, though they criticised Mr Shorten's political maneuvering.

Mr Entsch said he would seek to bring together a meeting of Liberal MPs who back the reform to discuss the issue as soon as next week, while he will also look to attend a cross-party meeting on the issue proposed by Senator Hanson-Young. Mr Entsch, Ms Hanson-Young and Mr Perrett are the chair and deputy chairs of the Parliamentary Friendship Group for LGBTI. Senator Hanson-Young, who has argued for same-sex marriage to be legal in Australia since entering the Parliament in 2008, said the Greens were keen to co-sponsor a marriage equality bill but would stand aside and allow Labor and the Liberals to take carriage of it if necessary. "If that's how things fall, so be it," she said. "We listened very carefully yesterday to the Prime Minister's comments...he's right, the only way to achieve marriage equality this year is by ensuring that everyone has ownership of it and everybody is willing to work together."

Australian Marriage Equality figures show Parliament is on the brink of having enough support to legislate same-sex marriage, with just one more vote to pass a bill in the House of Representatives. In the Senate, it is calculated a bill could pass with a majority of one. Follow James Massola on Facebook