The Tasmanian Greens will debate a motion that could give party members the power to block future power-sharing deals.

The proposal to be debated at the Greens' state conference today suggests some members are still unhappy with the previous power-sharing deal.

The 2010 state election ended in a hung parliament, and saw the Greens enter a balance-of-power deal with Labor.

After one term, the minority government was dumped.

The motion would require MPs to get the approval of selected party members before forming a minority government with another party.

Greens leader Cassy O'Connor, who was a minister in the Labor-Green government, said she would struggle to support the motion.

"We're the ones who are elected," she said.

"We're the ones who have to face the music. We're the ones who are accountable to the people who elected us.

"And I think we should be entrusted in those situations to make the best possible decision in the interests of Tasmania and in the interests of the party."

Outgoing convenor Austra Maddox argued the decision should be left entirely to the party executive.

"Of course there are wise heads in the party, people that have been around for a long time with a lot of experience, " she said.

"But I think it's actually a formal decision that needs to be made at the end of the day, so I think it should be the executive body."

The motion is being moved by the party's Bass branch.