Wilderness Society campaign manager Vica Bayley said he was overwhelmed by the turnout to the rally on the Parliament House lawns, adding that it would send a strong message in meetings this week, that many Tasmanians wanted the area to remain locked up.

The federal government has applied to the World Heritage Committee to remove the 74,000 hectares of forests added last year under the forest peace deal.

Delegations from the Wilderness Society, including Mr Bayley, will touch down in Doha, Qatar, today to try and stop the delisting.

Mr Bayley said it wasn't only the people who turned out to the rally who proved the site should remain listed.

``The value of the forests themselves show that they should be protected,'' he said.

``Most countries would die for places like this to be on the heritage list, yet we're trying to undo it. It's an atrocious message that we're sending to the rest of the world.''

Key speakers at yesterday's rally included University of Tasmania geography and environmental studies professor Jamie Kirkpatrick, Friends of Blue Tier's Leslie Nicklason and Bonorong Wildlife Sanctuary's Greg Irons.

No state government representatives will attend the meetings in Qatar this week.

Western Tiers MLC Greg Hall said the government had let the state down by not sending a representative.

``In effect, the Premier is saying the conservation movement can afford to send lobbyists, but we can't - That is appalling,'' Mr Hall said.

A state government representative said the government supported the federal government's election commitment to adjust the boundary of the World Heritage addition.

``This is now a matter for voting nation states, it is not a prudent use of taxpayer money to send a representative from the Tasmanian government to Doha,'' he said.

A result about the listing is expected to be known by Friday or Saturday.