The move would roll back the 1998 parliamentary deal between Labor and the Liberals that cut the number of MPs in the House of Assembly to the existing 25.

At the time the move was widely seen as an attempt to limit the potential for minority parties like the Greens to hold the balance of power.

Each leader will take the proposal to their respective parties for approval.

The proposal, signed by Premier David Bartlett, Opposition Leader Will Hodgman and Tasmanian Greens leader Nick McKim, calls for the House of Assembly to be restored to 35 members with seven members elected from each of the state's five divisions from the next general election.

There was no indication of a change in Legislative Council numbers. While Legislative Council President Sue Smith met the leaders on Monday, it is understood the talks were focused on the House of Assembly.

The proposal also includes provision for public consultation.

Mr McKim said the agreement was a "major milestone" for the Greens' 12-year campaign to restore the House of Assembly to 35 members.

"It is testimony to the opportunities presented by power-sharing parliaments, and a commitment to working together to deliver progressive outcomes for the community," he said.

"I sincerely thank David and Will for their constructive and collaborative approach, and I look forward to working with them to progress this issue to a resolution."

Mr Hodgman said the Parliamentary Liberal Party would meet later this month to consider the proposals.

"We have consistently and strongly argued that any proposed changes to the size of the House of Assembly must include consultation with the Tasmanian community," he said.

The proposal signed yesterday recognises that other parliamentary reform - including political donations, candidate expenditure, fixed parliamentary terms, the role and powers of parliamentary committees, a code of conduct for MPs, declarations of conflicts of interest and resources available to MPs - were more complex and required greater consultation.

The leaders resolved to examine these and other reform issues.