Gay marriage is legal in New Zealand.
The 77-44 vote in parliament on Wednesday night was greeted with cheers and applause from packed public galleries and kicked off celebrations around the country.
New Zealand is the 13th country to legalise gay marriage and the first in the Asia-Pacific.
More than 1000 Australian same-sex couples say they will cross the Tasman to tie the knot.
“Now that marriage equality is only three hours away there will be a flood of couples flying to New Zealand,” said Australian Marriage Equality spokesman Rodney Croome.
NZ Labour’s gay MP Louisa Wall promoted the Marriage (Definition of Marriage) Amendment Bill and it was passed on conscience votes, with no instructions from parties.
Prime Minister John Key was one of those supporting it.
MPs have been under intense pressure from churches and moral conservative lobby groups during the past few weeks but the final vote was almost identical to those cast during the bill’s previous three stages.
“Excluding a group in society from marriage is oppressive and unacceptable,” Ms Wall said when she launched the third reading debate.
“This is not about church teachings or philosophy, it never was. The principles of justice and equality aren’t served if the key institution of marriage is reserved for heterosexuals only.”
The Green Party’s gay MP Kevin Hague said he had been with his partner for nearly 29 years.
“Until this day a basic human right has been denied us,” he said.
“The consequences of this bill will be that same sex couples will marry, transgender people will no longer have to divorce, prejudice and violence will be undermined, the world will be a better place and absolutely no one will be any worse off.”
National’s Maurice Williamson, a strong supporter, said he had been appalled by some of the lobbying.
“I had a letter saying I was going to burn in the fires of hell, some of the bullying tactics were really evil.”
NZ First leader Winston Peters again called for a referendum.
“Some say there is a groundswell for change, but how do we know that?” he said.
“New Zealand is supposed to be a democracy and what we are about to do is circumvent any expression of public opinion.”
Mr Peters and his MPs voted against the bill.
Nearly all the MPs who spoke in the debate supported the bill.
One who didn’t was National’s Jonathan Young.
“History has invested significant tradition in marriage and I believe we should maintain that tradition,” he said.
“This issue isn’t as clear as some people think, many are struggling with it and the community is more divided than this parliament.”
Although Wednesday night’s vote put the bill into law, gay couples who want to marry will have to wait a while.
The Department of Internal Affairs which handles births, deaths and marriages has been given four months to get its act together and prepare the procedures and licence forms.
Ms Wall expects there will be a rush.
“The first week of August could work for a lot of people,” she told NZ Newswire.