The Tasmanian Greens have condemned the Government's gagging of debate on legislation to extend the proposed Tamar Valley pulp mill construction permits.

The Lower House last night passed the Pulp Mill Clarification Act, which extends the permits for the $2 billion Tamar Valley project until August 2011.

The Government says the original pulp mill permit act two years ago did not include a timeline and it introduced the amendment on the advice of the Solicitor-General.

Greens spokesman Kim Booth criticised the government for using the guillotine.

"Democracy is just as important in this state as the assessment of the pulp mill is," he said.

"What you've done now is ramped up the attack on democracy by springboarding, if you like, the original guillotine of the pulp mill bill bringing us back into this house and now guillotining debate," he said.