One of Tasmania's most vocal opponents to the state's forestry peace deal has joined the Liberal Party.

Michael Hirst from the Give it Back pro-forestry group will contest the seat of Lyons for the Tasmanian Liberals at next year's state election.

Mr Hirst said he has been spurred into politics after seeing the demise of an industry he has been passionately involved in all his working life.

"In the last three years seeing Tasmania dive to where it's going has made me stand up," he said.

"And I am delighted that Will Hodgman has taken me on board and I am more than happy to stand beside him and try and do something about it."