A fresh election has become a possibility should the July 2 poll result in a hung parliament.
In 2010, Julia Gillard sealed written agreements with the Greens and independent MPs to form government after the election resulted in the first hung parliament in seven decades.
The most recent opinion polls, which have Labor and the coalition level-pegging, raise at least the possibility of another hung parliament.
The debate kicked off in earnest on Wednesday morning when Labor frontbencher Tony Burke was asked whether a second election would be needed to resolve the deadlock.
"We certainly would not be forming any sort of coalition agreement with the Greens," Mr Burke told ABC radio.
Shadow treasurer Chris Bowen later told reporters in Sydney any minority government after July 2 would be determined purely by a vote of confidence on the floor of the House of Representatives.
"There would be no arrangements, deals, agreements, entered into," he said.
"Labor governs alone or not at all."
Asked whether he would rule out a second election, Opposition Leader Bill Shorten told reporters in Mackay: "Our aim is to win the first one."
"I'm not going to prejudge what the Australian people will do."
Prime Minister Malcolm Turnbull said Labor could not be believed when it came to dealing with the Greens.
Mr Turnbull pointed to the example of Greens MP Nick McKim, who worked with Labor to form minority government in Tasmania and was given a cabinet post.
"We know what Labor will do. If they need to do a deal with the Greens, they will do it," the prime minister told reporters in western Sydney.
Greens senator Sarah Hanson-Young said stronger action on climate change and a better way of handling asylum seekers would be "at the top of our list" if it came to a negotiation.
"On asylum seekers, we want to see those cruel camps closed and we want to see us giving a safer way for people to get to Australia," she told ABC radio.
Greens leader Richard Di Natale said in Perth the party would be open to a power-sharing deal with Labor, but not the Liberals.
"Ultimately it ends up being a negotiation. It would then be a decision up to the Labor party to decide if that's what they want," he said.
