Australia's parliament could legalise gay marriage this year if the government is allowed to let the public vote in a referendum, a senior minister has said.
The conservative Liberal Party-led coalition was narrowly re-elected in July 2016 with a promise to let people decide whether Australia should recognise same-sex marriage through a popular vote.
But in November that year, the senate blocked the move, which would have cost nearly £98 million, sparking a divisive public debate.
The Liberal Party, which held a crisis meeting on Monday night in a bid to resolve the in-fighting, rejected a push to allow politicians to decide the issue now.
The party will ask the senate this week to reconsider allowing the referendum. Voting on the plebiscite would be compulsory and failure to vote would be punishable by a fine.
The result would not be legally binding and some politicians have already declared it would not sway their vote on gay marriage legislation.
If the senate again blocks the plebiscite, the party proposes a voluntary postal referendum in which voters send in their opinions instead of using ballot boxes - a cheaper option that would not need the senate to approve the expense.
Responses would be voluntary and therefore less indicative of public opinion.
But opponents argue that the postal plebiscite would also need senate approval and have threatened a court challenge if it proceeds.
Finance minister Mathias Cormann, the government's deputy senate leader and an opponent of same-sex marriage, said on Tuesday that some type of plebiscite was essential if parliament was to decide the marriage equality question.
Parliament would decide the issue only if the vote found most Australians supported gay marriage.
"The truth is that there is a diversity of strongly and sincerely held views on both sides of the argument in our community and that is reflected in our party room," Mr Cormann said.
"The government has a timetable that would facilitate resolution of this issue by the end of the year, but ultimately there are some factors that are outside of the government's control," he added, referring to the hostile senate.
Senator Nick Xenophon, whose minor party opposed the plebiscite in the November vote, said gay marriage would become an election issue if the plebiscite was blocked by the senate or the courts.
"This is something that ought not to be put to a plebiscite, this is something that parliamentarians are paid for to decide and our position hasn't changed," he told Australian Broadcasting Corporation.
Anti-gay marriage advocates support the referendum, despite opinion polls showing that most Australians agree with marriage equality.
But gay rights advocates are concerned that referendums rarely change the status quo in Australia.
Lyle Shelton, managing director of the Australian Christian Lobby, said his advocacy group had collected 55,000 signatures on a petition demanding a referendum.
Mr Shelton handed the petition to Senator Cory Bernardi, leader of the minor Australian Conservatives party, to present to the upper house.
Mr Bernardi has said he would vote against gay marriage, regardless of a plebiscite result.
Mr Shelton was concerned that renegade Liberal senator Dean Smith had proposed a bill this week that allowed people who did not identify as either a man or woman to marry.
He said that furthered a gay agenda "queer theory" that gender was fluid.
Marriage equality would also cast doubt on whether religious schools could teach children that marriage was exclusively between a man and a woman, Mr Shelton said.
"This is not just about loving couples, if that was all that it was about, well, probably none of us would have too much concern," he said.