A self-executing bill is the "absolute minimum requirement" for Labor to support a marriage equality plebiscite, but more must be done if the government wants support for the controversial policy in the senate, according to shadow attorney general Mark Dreyfus.
At a press conference on Friday, Dreyfus said a plebiscite on marriage equality must have a binding result. That means the parliament would need to pass a marriage equality bill before the plebiscite that would come into effect following a successful "Yes" vote.
If the plebiscite is not self-executing, the government would not be bound at all to make same-sex marriage legal if the plebiscite were carried, Dreyfus said.
However, Dreyfus said a self-executing bill alone is not sufficient to win Labor's support.
He listed a number of things that would need to happen for the bill to gain Labor's support, including no public funding of the two opposing campaigns and compulsory voting.
"We’ve suggested that there should be no counting by electorate or by state, because that is irrelevant to a nationwide conclusion," he said. "We’ve suggested the need for careful consideration of material that might be associated with, or may accompany, the plebiscite."
Currently, the government looks to have secured 37 votes in the senate. For the bill to pass, it needs 39.
Labor will not make a decision until it sees the bill, while all but one of the Greens and the three Nick Xenophon Team senators have ruled out voting for it.
Last week, Greens senator Sarah Hanson-Young said she would vote for a plebiscite if there was no other path to marriage equality, leaving a door open for the government to scrape through if it can convince just one other person.