Former Australian prime minister Julia Gillard has changed her mind about same-sex marriage and now supports it.
In a speech at the College of Law and Justice in Melbourne, Ms Gillard said she was aware many remembered she had previously voted 'No' to same-sex marriage - a decision she described as "idiosyncratic".
"I am aware that this vote by me was viewed as odd by many, given what they know of my broader values. I am keenly aware my position was idiosyncratic," she said.
Ms Gillard said she had changed her view that heterosexual and same-sex couples should embrace civil unions.
"Given the 1970s feminist in me saw much to be concerned with from a gender perspective with traditional marriage, I thought the better approach was not to change the old but to create something new," she said.
"In my time post politics as key countries have moved to embrace same-sex marriage, I have identified that my preferred reform direction was most assuredly not winning hearts and minds."
Ms Gillard launched a strident attack on Prime Minister Tony Abbott's plan for a plebiscite or referendum on same-sex marriage.
She argued a popular vote on the issue was not needed and politicians should instead have a conscience vote after the next election.
"The only foundation stone for the idea of a plebiscite or referendum is an appeal to the all-too-popular sentiment that politicians are inadequate, that their decision-making is somehow deficient," she said.
"Enabling voters to express their views via the ballot box does not require a plebiscite or referendum.
"If all political parties had a conscience vote or clear policy, then in line with our normal democratic workings, people could question political candidates about same-sex marriage at the next election and decide to vote for a candidate who reflects their views."
Ms Gillard said if she was still in Parliament she would vote 'Yes'.
"I also think it is important that the matter is now resolved through a conscience vote by the Parliament as promptly as possible after the next election so that no more potential twists and turns can loom up," she said.
"I would not have a vote in that debate. But if I did, I would vote yes."
Advocates have welcomed Ms Gillard's decision to support marriage equality, saying it shows public figures can change their mind on the issue.
"We welcome Julia Gillard's decision because it shows that even the most high-profile opponents of marriage equality can open their hearts to the reform," Australian Marriage Equality national director Rodney Croome said.
"But we urge other political leaders not to wait until it is too late for them to show leadership in Parliament, as Ms Gillard has done."
The advocates have also condemned Mr Abbott's decision to keep alive the possibility of a referendum.
"The High Court has already defined marriage in the constitution, making a referendum unnecessary," Mr Croome said.
"Continued discussion of this incredibly expensive and dead-end option is a slap in the fact to the High Court and to our system of government."