Australia's Labour Party has blocked government plans for a public, but non-binding, vote on recognising gay marriage, arguing it would be better if the issue was decided in parliament.
Prime minister Malcolm Turnball's conservative coalition government needs the support of the opposition to get enabling legislation through the senate to hold a national vote on gay marriage on February 11.
Opposition leader Bill Shorten said that Labour lawmakers unanimously decided against the public vote, which is known as a plebiscite.
"The experts have unequivocally explained to Labour that the plebiscite would cause harm to gay and lesbian people particularly but not exclusively young people," Shorten said.
"Marriage equality, let's make it a reality, let's just get on with it," he added.
The Australian Christian Lobby, which opposes marriage equality, said it was disappointed "that ordinary Australians are being shut out from having a say about the biggest social policy change in a generation".
Opinion polls show most Australians support marriage equality, but gay rights advocates fear that an aggressive scare campaign could result in the plebiscite failing, putting same-sex marriage off the national agenda for decades.
Some conservative lawmakers have said they will vote against gay marriage in parliament even if a majority of Australians support it.
Attorney-general George Brandis accused Labour of being more interested in scoring a political win over the prime minister than doing the right thing for gay couples.
"Today is the opportunity for the Labour Party to show that it really does believe in marriage equality or whether it's just playing a political game here," he said before Labour made its decision.