Sydney - Newly-reinstated Australian leader Kevin Rudd put gay marriage on the election agenda on Friday, calling for a bipartisan conscience ballot on the issue and raising the possibility of putting it to a direct public vote.
Rudd, who took back power in a dramatic party-room coup on Wednesday from Julia Gillard who deposed him three years ago, said lawmakers from all parties ought to be allowed a conscience vote - where MPs vote on personal conviction rather than party lines - on the issue.
His ruling Labour party formally changed its position on the issue in December 2011 to pro-gay marriage but Rudd and his predecessor Gillard have both historically been against the reform.
There was a conscience vote on the issue last September which was defeated 98 votes to 42 after conservative leader Tony Abbott refused to allow opposition MPs to break with party lines, rendering it a null prospect.
Both Gillard and Rudd voted no in the September ballot but Rudd, a Christian, has since changed his position and challenged Abbott to a second vote where conservatives would be freed from party doctrine.
"Whoever wins the next election, please, let's just have the civility to open this to a conscience vote for all," Rudd said in his first press conference since being sworn in as prime minister.
If Abbott refused, Rudd said there were other options including a referendum or plebiscite putting the question directly to the Australian public for a vote because "I would just prefer to have this thing resolved".
"I would like to see this done, and the reason I want to see it done is frankly it causes so many people such unnecessary angst out in Australia, in the gay and lesbian community. It just should not be the case," Rudd said.
Same-sex unions are available in a majority of Australian states but because marriage comes under federal legislation these couples are not formally recognised as married by the government.
Labour has amended scores of national laws to remove discrimination against same-sex couples but have so far refused to allow them full marriage rights.
The option of a referendum is not popular with gay rights campaigners who fear an unpleasant and dangerous 'no' campaign by opponents, particularly extremists, stoking hatred and vitriol against gays and lesbians, and argue it is not for the public to vote on matters of basic human rights.