Government backbenchers will move a bill to legalize same-sex marriage in Australia in August with the support of two Opposition MPs and two independents.

Australia may yet join the United States and Ireland in legalizing same-sex marriage this year if a group of Government backbenchers, independents and Opposition MPs get their way.

Earlier today Sky News Australia broke the news that prominent Liberal/National Coalition supporters of gay marriage, Warren Entsch and Teresa Gambaro, had announced they would introduce a bill on the first Tuesday after Parliament resumes – which is August 11.

They hope to secure two backbenchers from the Labor Opposition to co-sponsor the bill and independent MPs Andrew Wilkie and Cath McGowan will also co-sponsor it.

It is yet to be seen whether Entsch and Gambaro will also seek co-sponsors from the Australian Greens – the party that has consistently championed the issue in the Parliament over the last decade.

Prime Minister Tony Abbott has previously said that a non-partisan bill was the condition on which he would consider allowing a free vote on his watch.

Entsch and Gambaro plan to have the Liberal party room debate whether Government MPs should be allowed to have a conscience vote on the issue and if that is secured the bill would then be put up for a vote in both the House of Representatives and Senate.

The campaign for marriage equality in Australia, Australian Marriage Equality, has previously said it believes such a bill would pass in the Senate and that it would also find a narrow majority of support in the House of Representatives – though they are continuing to work to shore up support in both houses of Parliament.

‘Because this bill will be signed by two Liberals it will have the best chance of achieving a Coalition free vote, and because it has cross-party support it has the best chance of passing,’ Australian Marriage Equality national director Rodney Croome, said in reaction to the bill.

‘With momentum growing after marriage equality in Ireland and the US, this bill gives Australia the strongest opportunity we have ever had of achieving marriage equality. We aim to win majority support in parliament with grassroots mobilization, rallies and advertising campaigns throughout July and across the nation.’

Croome said that it seemed impossible that the Liberal Party would refuse a free vote on a bill that came from within its own ranks.

‘It is untenable for Coalition MPs to introduce legislation they can’t vote on,’ he said.