Australia's prime minister gave a personal assurance on Friday that his government would legalize gay marriage if a majority of Australians choose marriage equality in a popular vote.
The center-right government has promised to hold a plebiscite on the gay marriage question if the government is re-elected in a vote due this year.
But a number of the government's most conservative lawmakers have recently announced that they might vote down gay marriage against the wishes of a majority of Australians.
Prime Minister Malcolm Turnbull, who supports gay marriage, said his government would "absolutely" follow the result of the plebiscite.
"If the majority of people voting in the plebiscite vote in favor of it, then same-sex marriage will be legalized," Turnbull told Melbourne Radio 3AW on Friday.
The center-left opposition Labor Party supports gay marriage. But the ruling coalition is bitterly divided on the issue.
Former Prime Minister Tony Abbott, a former Roman Catholic trainee priest who opposes gay marriage, had proposed last year that a plebiscite be held after the next election as a way to end the political in-fighting by effectively taking the decision out of lawmakers' hands.
Opponents argue the plebiscite would cost about 160 million Australian dollars ($113 million), and carry no legal weight so the question would still be left to Parliament to decide.
Turnbull had wanted parliament to decide the issue, but after replacing Abbott as prime minister in September he decided to leave that part of government policy unchanged.
Federal plebiscites, which unlike referendums carry no legal weight, have been held only three times since the Australian government was formed in 1901. Two rejected conscription during World War I, and a third in 1977 replaced "God Save the Queen" with "Advance Australia Fair" as the national anthem.