The federal government is still holding out hope Labor will change its mind and support a plebiscite on same-sex marriage.
The proposed national vote, which the coalition took to the last election, appears doomed after the opposition this week formally rejected the idea.
But cabinet minister Josh Frydenberg denied Australia would have to wait for a Labor government to get marriage equality.
"I think that the Labor party may come to their senses and recognise the surest, fastest way to same-sex marriage is through a plebiscite," he told ABC radio on Friday.
"Certainly I, the prime minister and many others who believe in same-sex marriage believe that that is the best option we have."
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Former prime minister Tony Abbott, the plebiscite's architect, said marriage was a very personal thing and pre-dated the Australian parliament.
"That's why I think this is one of the few subjects which, quite properly, ought to be decided by the whole people and not just a few of the people," he told Sky News on Thursday night.
