Former Labor premiers Paul Lennon and Michael Field and former Liberal premiers Robin Gray and Tony Rundle joined forces to urge voters to demand details of how the Tasmanian Greens would negotiate support in the event of a minority government being elected in Saturday's state poll.

Mr Lennon said the two most recent examples of minority governments in Tasmania - led by Mr Field and Mr Rundle respectively - had ended in disaster.

"That's despite the fact that on both occasions the Greens promised stability," he said.

"We don't want this to happen again and so we are urging Tasmanians to firstly seek some honesty from the Greens about the conditions they require to support either major party and then, when they come to vote on March 20, to think very carefully about the consequences of minority government.

"(Greens leader) Nick McKim must state very clearly what demands the Greens would make in return for stability."

Mr McKim dismissed the former premiers' views, labelling them "dinosaurs".

The joint statement from the past Liberal and Labor party leaders came just before tomorrow's release of an exclusive Sunday Examiner poll.

Last month an Enterprise Marketing and Research Services survey put statewide support for the Greens at 22 per cent, up from 15 per cent at the February 2009 poll.

Mr McKim said that he was not surprised by the views of the former premiers, who would "prefer a government with the absolute power that allows secrecy and cronyism, rather than a power-sharing arrangement that will deliver the stability, accountability and transparency that has been so lacking over the last four years of majority government.

"These gentlemen are clearly worried that the Greens' focus on reducing the cost of living shows up the fact that the parties they represented have abandoned Tasmanians struggling to make ends meet.

"These old premiers are just dinosaurs howling in frustration at a new dawn in Tasmania."

Political analysts Peter Tucker and Richard Herr both described the move as an act of desperation.

Professor Herr said that the campaign may work to remind voters of the "collusion" between the Liberal and Labor parties in 1998 to reduce the size of parliament and "get rid of" the Greens.

"It's possible that this will only consolidate the Green base in terms of reminding (voters) of what was done to destroy the Parliament to get rid of the Greens," he said.

Mr Tucker also had doubts about whether the campaign would be successful.

"In this campaign the voters, to me, seem to be less concerned about minority government than in the past," he said.

Professor Herr said that he did not agree with the sentiment of the campaign.

"The reason you have a vote is to vote your interest; you shouldn't vote someone else's interest," he said.

"The idea that people should not vote their interest doesn't strike me as an appropriate way to promote democracy."