They're the party neither leader wants.
Both Malcolm Turnbull and Bill Shorten have told the Greens there's no chance of the minor party forming an alliance with a minority coalition or Labor government in a hung parliament after July 2.
Greens MP Adam Bandt raised the prospect of a coalition with Labor, saying his party would be "up for it".
The Labor leader's response was blunt, echoing The Castle's Darryl Kerrigan: "Tell 'em they're dreaming."
"No deals with Labor about forming a coalition. No deals," Mr Shorten told reporters in Townsville on Tuesday.
The prime minister didn't mix his words either, saying there was "absolutely no chance" of any joint arrangement between the coalition and the Greens.
"But I can tell you Labor won't (rule it out) and Labor can't and if they did no one would believe them," Mr Turnbull told reporters in Brisbane.
"It will be same old Labor, same old deal with the Greens, Julia Gillard's government being re-enacted by Bill Shorten."
Mr Bandt said any Labor refusal to negotiate would be "pig-headed".
With opinion polls showing Labor would struggle to win an absolute majority in parliament's lower house, voters were entitled to know what the Greens would do in that situation, he said.
Greens leader Richard Di Natale said it was inconceivable his party would team up with the coalition.
Mr Shorten says splitting the progressive vote would be the worst result for working people.
"They try to say to Labor voters you can have your cake and eat it too, you can vote for us and really it's a vote for Labor. It's absolutely not," he said.
He claimed the Greens weren't running seriously against any Liberals, accusing the minor party of doing a deal with the conservatives over preferences in inner-city seats.
Deputy Labor leader Tanya Plibersek said ALP negotiators in Victoria had been told all seats in that state were off the table.
"Melbourne, Batman, Wills there's a deal done," she said, referring to Mr Bandt's seat and two inner-city Labor electorates.
Senator Di Natale is adamant his party won't be preferencing the Liberals over Labor anywhere in the country.
"Ultimately the (branches) will make a decision about whether they want to recommend preferences at all," he said.
Mr Turnbull wouldn't rule out doing preference deals with the Greens, saying that was a matter for the Liberal Party organisation.
