Just one day after being sworn in, Australian Prime Minister Kevin Rudd has announced his intentions to hold a referendum on same-sex marriage unless a free vote is held.

Following a leadership ballot, Mr Rudd took over the role from Julia Gillard, who is strongly opposed to equal marriage.

She confirmed on Wednesday that she would resign as Australia’s Prime Minister in favour of Mr Rudd – with LGBT campaigners welcoming the news.

He announced today that unless a free vote is given to all Australian parliamentarians on the issue, he would push for a referendum.

“I would like to see this done,” he said. “It causes so many people such unnecessary angst out in Australia, in the gay and lesbian community.”

Mr Rudd announced his support for equal marriage in May, having previously been against it.

The 55-year-old said he had come to “believe the secular Australian state should be able to recognise same-sex marriage”.

Australian Marriage Equality national director, Rodney Croome, warned that a referendum was a less than ideal way of achieving equality, as cross-party support would still be required to pass a law.

He said: “It would lead to fear-mongering against the gay and lesbian community and, either a referendum or a plebiscite, would not lead to a change in the law directly.”

However, he welcomed Mr Rudd’s return to leadership.

“Having a prime minister who supports marriage equality opens up a new chapter in the debate by mainstreaming and legitimising the reform like never before,” he said.

Mr Rudd’s support is in stark contrast to Julia Gillard, who said on becoming prime minister in 2010: “We believe the Marriage Act is appropriate in its current form, that is recognising that marriage is between a man and a woman, but we have as a government taken steps to equalise treatment for gay couples.”

She ruled out introducing equal marriage in May following neighbouring New Zealand’s decision to introduce the measure.

Along with Julia Gillard, Australia’s opposition leader Tony Abbott continues to oppose equal marriage and refuses to allow his Liberal MPs a conscience vote.