LABOR’S factional leaders are poised to strike a deal to declare the vexed issue of same-sex marriage a conscience vote in order to defuse a potential brawl on the floor of December’s national conference.

They fear a divisive debate on the issue would dominate media coverage of the conference, creating the impression the Greens – advocates of same-sex marriage – are dictating the agenda of Labor’s supreme policymaking body. The move is also partly designed to shield Julia Gillard, who opposes same-sex marriage, from being rejected on the issue by her own party.

And it would potentially reduce the chance of any bill in favour of same-sex marriage passing through parliament.