The Australian government has proposed a date for a compulsory plebiscite on same-sex marriage, as concerns over expense and funding fuel opposition to the plan.
The government has provisionally set the date for the vote for Saturday, February 11, 2017, a statement from the Australian Attorney General's office said on Tuesday.
The ballots would ask voters: "Should the law be changed to allow same-sex couples to marry?"
Voting will be compulsory, the Attorney General George Brandis said.
Before Prime Minister Malcolm Turnbull can vote yes, as he has pledged to do, he must lobby the opposition Labor party to pass a parliamentary bill for the vote, which the premier said he will introduce this week.
Turnbull will need Labor's backing for the legislation to pass, since some of his own Liberal party members are set to cross floor and vote against the bill, including Dean Smith, the party's first openly gay federal member of parliament.
Smith said the idea of a plebiscite is "abhorrent" and that he will abstain from voting.
A plebiscite in Australia differs from a referendum in that it does not relate to constitutional matters.
The government has set aside 170 million Australian dollars (127 million US dollars) for the proposed poll, which would be determined by a simple majority.
The Attorney General's office said the government plans to fund both the "yes" and "no" campaigns. The advertising committees for both sides are to receive a grant of 7.5 million Australian dollars (5.6 million US dollars) each.
A heated debate broke out in parliament on Tuesday as opposition deputy leader Tanya Pilbersek asked why the prime minister would spend taxpayers' money on a "no" campaign.
She was joined by Eddie, the 13-year-old son of same-sex parents.
Turnbull said: "Eddie will understand that everything we do here in this parliament is designed to ensure that Australia becomes an even better place for him to grow up in and realize his dreams."
"We respect them [his parents], we respect their family and we will respect the love they have for their boy."
The Greens and other independent candidates have also voiced their opposition to the plebiscite.
Opposition leader Bill Shorten has called the plan too expensive, instead proposing a separate bill on Monday to legalize same-sex marriage via a parliamentary vote.
On Tuesday, he stopped short of committing to blocking the bill.
"We are going to be talking further to people who will be affected by this vote. We will be talking further to mental health experts," Shorten said.
Another Labor lawmaker Graham Perrett said the plebiscite had "a snowflake's chance in hell" of getting through the senate, where the governing coalition holds even less seats.
The plebiscite was one of the major agendas by Turnbull in the July election, which his coalition won by one seat.
The current Marriage Act 1961 does not allow for same-sex couples to get married.
A poll last month carried out by Essential found that 62 per cent of people supporting same-sex marriage in Australia.
According to the latest Newspoll published in the Australian on Tuesday, Turnbull's approval rating has dropped below Shorten's for the first time.
Dissatisfaction with his performance reached a new high of 53 per cent, which is more than double what is was when he became prime minister 12 months ago, compared to Shorten's dissatisfaction rate at 52 per cent.