Andrew Barr has pledged to use his historic status as the nation's first openly gay head of government to continue to advocate for same-sex marriage in Australia.
Moments after receiving a standing ovation on his election as the ACT's seventh Chief Minister, Mr Barr paid tribute to his long-term partner Anthony Toms who was watching on from the crowded public gallery.
"Anthony, I love you and I look forward to the day when we can legally marry in this country," an emotional Mr Barr said.
His elevation comes after a 15-year partnership, defined by the couple's 2009 civil union and long-standing advocacy for equality for gay and lesbian Australians.
Mr Barr thanked his parents and siblings and promised to call on the support of the Labor faithful as he takes over from the outgoing Katy Gallagher.
The 41-year-old won national praise when he worked with South Australian Senator Penny Wong to change the Labor Party's national platform to support same-sex marriage in November 2011.
Central to the ACT's historic, if shortlived, marriage reforms passed in 2013, Mr Barr promised to continue to fight for change on an issue he said required action from the federal Parliament.
"A number of people have observed, and I agree, that it is quite ironic that you can be elected chief minister, first minister of a jurisdiction, but you can't marry your partner of 15 years," he said in a press conference.
"I want to assure gay and lesbian Canberrans, and indeed Australians, that I will continue to be a passionate voice for reform in this area."
The couple met at a Canberra festival in 1999, choosing not to marry before the High Court overturned same-sex marriage last year, reluctant to put the spotlight on themselves.
Mr Barr said in a 2012 interview that he would like to have children after his political career.
Having overcome gossip and attacks in some party circles in the past, Mr Barr joins the ranks of Senator Wong, former Greens Leader Bob Brown and other prominent gay leaders in Australian politics.
"It is time this discrimination is ended in this country and I will continue to be a loud and passionate voice for that change," he said.
"I know I have the very strong support of the overwhelming majority of Canberrans and the overwhelming majority of Australians for that change to occur."
He called on Prime Minister Tony Abbott to give Coalition MPs a conscience vote on the issue immediately.
A poll by Liberal pollsters Crosby Textor earlier this year found 72 per cent of Australians supported same-sex marriage and 77 per cent believed Liberal and National Party MPs should be granted a conscience vote.
"I am certain there is enough support within the Parliament for this change if only members were allowed to vote how they truly believed," Mr Barr said.
"The Australian public are so far ahead of Australia's parliaments and that is disappointing and it's important that parliamentarians catch up with what is an overwhelming sense … that it is time for change."
He said Mr Abbott should follow the lead of conservative governments in the United Kingdom and New Zealand in recognising access to marriage as a human right.
"It is remarkable to think Australia is lagging so far behind some of our closest partners and allies and countries that share so similar a cultural heritage.
"I urge every member of federal Parliament to reflect deeply on this and to look into their conscience and support marriage equality in this country," Mr Barr said.
Last month, Liberal Democratic Senator David Leyonhjelm introduced a private members' bill to allow same-sex marriage. Mr Abbott said before the 2013 election that a new Coalition party room would decide if MPs should have a conscience vote on the issue.