The Senate has launched an inquiry into the Federal Government's plan to delist part of Tasmania's Wilderness World Heritage Area.

Yesterday the Senate yesterday passed a Greens motion condemning the move to delist about 74,000 hectares added last year under the Tasmanian Forest Agreement.

It will now look at how the Government went about re-evaluating the area and the interaction between the Prime Minister and Environment Department.

It will also examine the implications the move could have on the area's World Heritage status.

The Government says a large part of the area added last year has been logged in the past and is not worth protecting.

Environment Minister Greg Hunt accused the previous Labor Government of ramming through the extension without the backing of the local community.

Signatories to the forest agreement and the State Labor Government say removing some of the forests would re-ignite the forest wars and damage the industry's reputation.

The Senate committee conducting the inquiry will report by mid-May.

The World Heritage Committee is due to announce its decision on the Federal Government's bid in June.