Australia's first legally recognised same-sex weddings could take place as early as December, after the ACT Legislative Assembly approved historic marriage equality laws.
Same-sex couples from around Australia will be able to marry under the law, which supporters say will help transform the ACT into a "rainbow territory''.
The ACT government has promised to consider legal advice recommending changes to the law to strengthen its chances of surviving the High Court challenge being planned by the federal government.
Supporters of same-sex marriage wept and sang Love is in the Air after the bill was approved by the 17-member Assembly with the support of all eight Labor and the sole Greens MLA.
Deputy Chief Minister Andrew Barr, who is gay, told the Assembly that the law would help transform many lives and Canberra into a "rainbow territory'' or "city of love''.
''It marks an important step in our journey to become the most LGBTI [lesbian, gay, transgender and intersex friendly] city in Australia,'' Mr Barr said.
"Whether it's the rainbow territory, the city of love, it's an important journey for us. I have no doubt that this reform will transform many lives.''
Mr Barr choked back tears as, in the debate, he discussed the struggles faced by gay and lesbian people, their families and supporters.
Chief Minister Katy Gallagher said the threat of a High Court challenge would not deter the government from proceeding with the establishment of a local same-sex scheme: ''That should not deter us, it doesn't rattle us and it doesn't change our path.'' She said marriage equality was necessary to end discrimination against same-sex couples.
''It's a proud day for the government and I know for many across our community,'' she said.
''We on this side of the chamber are prepared to challenge outdated legal notions and meet our responsibilities … to make sure that each and every one of you is treated with recognition, equality and fairness before the law.''
The marriage equality law is expected to be operational within a fortnight. Due to a requirement that they give a minimum of 30 days notice, couples will be unable to marry before early December. During the debate, Attorney-General Simon Corbell moved several amendments designed to reduce the risk that the same-sex marriage law would come into conflict with the federal Marriage Act.
But some marriage equality advocates believe further amendments to the law are necessary to minimise the risk it will be struck down in the High Court.
Ms Gallagher said the government had agreed to meet with legal experts to discuss their concerns but was not yet convinced of the need for further changes.
Greens minister Shane Rattenbury said changes could be made to the law if the legal advice demonstrated that they were warranted.
"It's important we look at it in close detail and see if it offers anything that we might further consider. It would be unwise of us not to listen to people who have great expertise in these areas,'' Mr Rattenbury said.
The bill was opposed by all eight Liberal MLAs although the only one to speak during the debate was party leader Jeremy Hanson.
Mr Hanson said marriage was a federal matter and should be debated by the ACT legislature.
''We believe that this issue belongs in the Commonwealth Parliament,'' Mr Hanson said.
''It is a federal issue and there are a wide-range of sound legal opinions that support that position.''
Mr Hanson said he doubted that amendments to the bill moved by Mr Corbell would ensure the bill was constitutional.
''It is a leap of faith now to accept Simon Corbell's assurances that the amendments will make this bill lawful when he's spent the last few weeks arguing against the need for any such amendments, he said.
Rodney Croome, national director Australian Marriage Equality, praised the ACT government for fulfilling an election commitment to introduce same-sex marriage.
''Regardless of concerns about the bill, all Australians who support marriage equality are in a great debt to the ACT government,'' Mr Croome said.
The bill was passed "in principle'' by nine votes to eight. But the final vote was eight votes to seven after Labor MLA Mary Porter agreed to a "pair" arrangement with Liberal MLA Andrew Wall in order to enable Mr Wall to attend an appointment.