Prime Minister Julia Gillard says she won't be moved from her stance against gay marriage despite New Zealand passing legislation allowing same sex couples to tie the knot.
Asked by a member of the public at a community cabinet in Melbourne on Wednesday night why Australia lagged behind New Zealand in legalising gay marriage, Ms Gillard said she would not be changing her mind on the issue.
"I doubt we're going to end up agreeing," Ms Gillard said.
She told the community cabinet at Ringwood that Labor has allowed a conscience vote on the matter.
As Ms Gillard was speaking at Ringwood, a conscience vote in New Zealand parliament passed the Marriage (Definition of Marriage) Amendment Bill with a convincing 77-44 vote.
New Zealand is the 13th country to legalise gay marriage and the first in the Asia-Pacific.
Independent Sydney MP and gay rights activist Alex Greenwich said the vote showed the campaign for gay marriage was "unstoppable".
"I wanted to come over here and see that it can happen," Mr Greenwich told reporters in Wellington.
He said the vote gave "a lot of hope and a lot of encouragement to campaigns in Australia".
"The growing international pressure that was just taken up a notch with New Zealand embracing this important reform is sending a message that marriage equality is unstoppable," he said.
"If New Zealand can do it, Australia can as well."
Australian Marriage Equality national convener Rodney Croome labelled the vote a "game changer".
"This will be a game changer in Australia because of the close links between our two countries," he said in a statement.
Mr Croome expects as many as 1000 gay couples will now cross the Tasman to get married.
"Now that marriage equality is only three hours away there will be a flood of couples flying to New Zealand," he said.
Last year, an attempt to legalise gay marriage failed in the Australian parliament, with Ms Gillard opposed to the move, and Opposition Leader Tony Abbott refusing coalition MPs a conscience vote.