All three leaders pledged future projects of significance would undergo independent assessment.

Opposition Leader Will Hodgman said a middle ground must be found.

"I do believe that we need greater certainty and consistency in our planning processes, removed from political interference because it undermines public confidence," Mr Hodgman said.

"I believe that the planning process should have the capacity to hear concerns of interested parties and people in Tasmania but can't be open ended and nor should it be because that creates uncertainty in itself."

Greens leader Nick McKim said major projects must be subjected to an independent assessment process.

Mr McKim questioned how Tasmanians could have confidence in Premier David Bartlett and Mr Hodgman after they supported the "dodgy and corrupt" pulp mill assessment process.

"The Greens will always stand up for Tasmanians and Tasmanian communities to have a real say in planning decisions that can impact on their day to day lives - that is a fundamental philosophy of the Greens and we will never, never let you down on that."

Mr Bartlett brought sections of the audience to laughter when he conceded that "some people" were unhappy with the pulp mill approval process.

Mr Bartlett said the State Government had already legislated planning reform so projects of regional significance were referred to an independent expert panel.

"Government will have no role in the decision making and has no capacity to change the decision," he said.

"I am proud, as Premier, to have introduced those reforms into our planning system."