Attorney-General George Brandis, charged with designing the plebiscite on same-sex marriage, has demanded Labor "get out of the way" and support a public vote on marriage equality.
Senator Brandis also said the majority of the LGBTI people with whom he had spoken to recognised the "surest" and "most direct" course to marriage equality was a plebiscite, given the government's election commitment.
"I very much hope that the Labor Party gets out of the way on this and Bill Shorten doesn't succumb to the temptation to play politics with the issue," he told the ABC's Lateline program on Monday.
"Mr Shorten needs to know that if the Labor Party decides to stop the plebiscite bill, then they will have stopped gay marriage for the foreseeable future."
The Attorney-General made the statement after a day of intense political bickering over the planned plebiscite, which now stands to be opposed by the Greens, the Nick Xenophon Team and possibly Labor.
If Labor does join in blocking the bill, it will fail to pass the Senate - and in all likelihood put same-sex marriage on the backburner for the next three years.
Labor is calling on the Turnbull government to dump the $160 million plebiscite, which it says will unleash a campaign of homophobia and hatred, and instead allow a free vote in Parliament. Based on MPs' public statements, such a vote would see same-sex marriage legalised.
But Senator Brandis told Lateline that "the only way" the government could deal with the matter was through a plebiscite, which it had promised at the July 2 election.
He acknowledged that for many LGBTI people, a plebiscite was "not the preferred option". But, he argued, "most of the people to whom I've spoken are sensible and pragmatic enough to know that the surest course, the most direct course now, to the outcome that they want and which I support is through a plebiscite".
The Attorney-General will now come under pressure to release details about the plebiscite, including the proposed question and structure, before Labor makes a final decision. While the opposition hardened its rhetoric over the past week, it has left the door open to supporting the plebiscite, particularly if it regards the question as fair.
The government has hinted the vote could be held in February, but has not commented on whether both sides will receive public funding for their campaigns.
