Federal Labor Senator Penny Wong has dismissed claims the party has pressured a colleague to publicly change their stance on marriage equality.
Tasmanian senator Helen Polley, who is voting against same-sex marriage, says she has been told she will cost her party votes at the next federal election.
"I've been told that I could be responsible for losing the next federal election," she told The Australian newspaper on Monday.
But Senator Wong says the party has a free vote on marriage equality and the majority of Labor MPs and senators support it.
"Helen's position (on marriage equality) has been well known for a very long time, for as long as I've known her, and she's entitled to hold that view," Senator Wong told reporters in Perth.
Asked if she supported the right of Labor MPs and senators to vote 'no', she replied, "I uphold the rules of the party and the party has gone through a lengthy process here of resolving its position and the overwhelming majority ... will be voting yes."
Labor frontbencher Andrew Leigh told Sky News he was unsure what Senator Polley had been told, but agreed the majority of his colleagues were backing marriage equality.
Dr Leigh acknowledged members would not get a free vote after the next election, with Labor committing to support same-sex marriage as a whole.
He is confident the postal survey, which closes on November 7, will be successful and allow the issue to be resolved before the year ends.
