Tasmania has become the third Australian state to pass a motion in support of same-sex marriage, following a lengthy debate on Wednesday night.
Liberal premier Will Hodgman and deputy premier Jeremy Rockliff both threw their support behind the Greens motion, which passed the Tasmanian lower house 15-9.
Tasmania joins New South Wales and Western Australia as the third state to pass an in-principle motion in support of marriage equality. However, only the Australian federal parliament can actually legislate the reform.
Tasmania was the last state in Australia to decriminalise sex between men in 1997. Since then, the state has become a frontrunner in terms of LGBTI rights by recognising same-sex unions, allowing same-sex adoption and introducing anti-discrimination protections.
"I'm offended by the notion that our community says same-sex couples are less capable of love and commitment and marriage than heterosexual people," Hodgman said during the debate.
"We live in a world that contains non-traditional relationships, de facto, single-parent, significant relationships, same-sex relationships," he added.
"I don't believe [that] same-sex marriage in 2015 will affect the sanctity of the institution of marriage."
Deputy premier Jeremy Rockliff said he has supported same-sex marriage for "some years now" and was happy to put his views on record.
"I believe very firmly that those who are committed and in a loving relationship should have the ability by law and the eyes of the law in society that if they have chosen a significant other to spend the rest of their lives with then they should be able to get married."
"In years to come we will actually really wonder why it took so long to get to this point."
The 15 votes in favour included seven Liberal MPs, five Labor and three Greens.
Of the nine MPs who voted against the reform, several cited religious beliefs and the rights of children as their concerns.
"Children deserve to grow up with at least the chance of a mum and a dad; same-sex marriage would deny them that right," said Liberal MP Guy Barnett.
"If same-sex marriage is passed we will enter in my view a whole new era, an era where gender will not matter anymore."
National director of Australian Marriage Equality Rodney Croome said the vote showed that "the arc of history is bending to marriage equality".
In particular, Croome paid tribute to the Liberal MPs who supported the motion.
"They have sent a strong message to their colleagues in Canberra that it's time to support marriage equality and a strong message to the nation that Tasmania is an inclusive and tolerant society," he said.
"The fact the Tasmanian Liberal Party had a free vote on the motion sets an important precedent for the federal Liberal Party to have a free vote on marriage equality legislation."
The Australian Christian Lobby is disappointed by the vote, describing it as the Tasmanian parliament "caving in to the Green ideological agenda".
"It is particularly sad that so many Liberal MPs have, in a relatively short space of time, been swayed to change their views on the timeless institution of marriage," said Tasmanian ACL director Mark Brown. "One can only ponder why."
Brown condemned the "aggressive and relentless campaigning" around same-sex marriage as contributing to the swing.