But a former High Court judge argues there's little point of a public vote and parliament should just get on with the job it is supposed to do.
Michael Kirby, who has lived with his partner Johan since 1969, hopes the Senate will deny support for what he believes is an unnecessary and expensive exercise.
In a ten-point take-down of the plan, Mr Kirby says a plebiscite defeated would effectively kill off the reform, possibly for decades.
He believes Australia's record on successful constitutional referendums is abysmal and there is no reason to hope this vote, proposed to be held next year, would be an exception to the rule.
"It would be better that nothing at all were done by the federal parliament on same-sex marriage than that a plebiscite was undertaken with a possibility of defeat," Mr Kirby writes in The Australian on Tuesday.
But Liberal backbencher James Paterson says the issue has been extensively dealt with and debated in parliament.
A plebiscite was a reasonable solution to what appeared to be a parliamentary deadlock.
"If same-sex marriage advocates put their shoulders to the wheel early enough in the process then they'll have the outcome that they want," Senator Paterson told Sky News.
"But continuing to fight the last war, trying to stop the plebiscite I think is not the right strategy for people who want to see same sex marriage legalised in Australia."
Labor backed Mr Kirby saying he was right in arguing it's been almost a century since Australia held a plebiscite on a policy issue.
"It's not the norm of representative democracy in Australia," opposition frontbencher Matt Thistlethwaite said.
