The Victorian Greens are hitching their wagon to Labor for this month's state election, preferencing its candidates over the Liberals in every seat.
State party leader Samantha Ratnam confirmed the arrangement on Wednesday and called on Labor to repay the favour by preferencing the Greens and other progressive candidates ahead of the Liberals.
"If Labor is serious about a progressive parliament, they must commit to preferencing the Greens and progressive independents ahead of the Liberals across the state," she said.
"What the Liberals do is up to the Liberals. We have not met with them and there is no Greens-Liberal deal."
They have also urged all parties to put far-right and religious-right groups last in their preferences ahead of the opening of early voting centres on Monday.
"Parties like One Nation, United Australia Party and Freedom Party are anathema to the vast majority of Victorians," Ms Ratnam said.
"Family First and DLP (the Democratic Labour Party) are running on explicitly transphobic and homophobic campaigns and their politics of hate has no place in the Victorian parliament."
Spokesman for Family First, Lee Jones, described the claim as a baseless slur, calling on the Greens to stop name-calling and start engaging in policy debates.
"Family First is simply fighting to protect Victorian families from the threat of radical political correctness. That has nothing to do with being 'phobic'," the upper house candidate said.
It comes amid a report the Liberals are plotting to preference the Greens over Labor in pivotal seats, in keeping with its election slogan to "put Labor last".
Opposition Leader Mathew Guy said preferencing decisions ultimately lie with Liberal State Director Sam McQuestin but he would discuss it after nominations are finalised.
"I'll have a chat with the state director when it becomes relevant. We still don't know who's standing where. Let's wait until we get to that point," he told reporters in Frankston.
Premier Daniel Andrews said the mooted move was a matter for the Liberal Party and wouldn't be drawn on whether he was worried it could affect Labor's chances to retain seats like Richmond and Northcote.
"We have a preferential voting system. The choices of others are one thing and then the choices of voters, we'll see how that plays out," he said.
Mr Andrews has already ruled out striking a deal with the Greens to form a Labor minority government in the event of a hung parliament after the November 26 election.