Tasmanian Greens leader Nick McKim was Saturday still pondering whether to join the cabinet after being invited by Tasmanian Premier David Bartlett .
The move was anticipated, and McKim has until Sunday to accept the offer.
Mr Bartlett and Mr McKim have been discussing a power sharing arrangement for the past three days, after the Labor leader was commissioned by Governor Peter Underwood to test his numbers in the lower house.
The March 20 poll delivered a hung parliament, with the Liberal and Labor parties claiming 10 seats each and the Greens winning the remaining five.
Mr Bartlett said he would work out what ministry Mr McKim would be given before next Wednesday, assuming he accepted the offer.
"It is my intention to do all that I can to make this parliament work," Mr Bartlett told reporters in Hobart on Friday.
The offer says that Mr McKim would be bound by cabinet confidentiality, but is not obliged to vote with the government on "matters of significant concern".
Despite a clause saying Mr McKim would be required to support the government in matters of supply and in confidence and no confidence motions, Mr Bartlett said it was not a deal, which he had spoken out against during the election campaign.
"I define this as a letter of invitation to Mr McKim and a set of protocols that go with that," he said.
"But I accept that commentators, people in Tasmania and further afield will call it a variety of things.
"What it's called doesn't matter that much. What it is, is a genuine attempt to make this parliament work."
Mr Bartlett said the government was now in uncharted waters.
"This has never happened in Tasmania before," he said.
"We won't always agree, and that's for sure.
"But what's important, and the things we do agree upon is that we do our best by Tasmanians."
Shortly before the letter of offer was made, Mr McKim said he would take any offers of ministry to his party room.
"As the model (of government) is being developed, I think that it is now reflecting... a model which may well allow for a cabinet to function properly with members from different political parties," he said.
