A government spokeswoman declined to give a reason why Ms Giddings did not attend the rally but had offered to meet a delegation of six attendees.

Timber workers' main objection to the $276 million agreement is that 430,000 hectares of native forest have been placed in an informal reserve.

Truck horns were blown in a short procession as families and workers chanted, waving placards which called for an early election and warned workers would not be "sold out".

Westbury farmer Dimity Hirst, who helped organise the rally, said almost 2000 people from around the state had attended. "So many Tasmanians will be unknowingly affected by the deal," she said.

"What is going to happen to our children's futures and our small communities?"

The crowd has gathered on the lawns of Parliament House to be addressed by politicians and industry representatives.

Opposition Leader Will Hodgman described the deal as a "politically motivated sellout" by Labor to appease the Greens who hold the balance of power in Parliament.

"The deal will destroy an industry, decimate local communities and leave thousands unemployed," he said.

"And the peace we were promised is just a mirage - environmentalists are still protesting and still disrupting logging shipments."

Greens forestry spokesman Kim Booth said forest contractors and their workers were wrong to target the government over the forest solution and instead should direct their anger at timber industry heads and the Tasmanian Liberals.

"These workers deserve better than big company self-interested distortions and untruths," he said. "They deserve an explanation from industry representatives and the Liberals why they shouldnt get the $45 million for exit packages, $40-plus million for training and employment support, or why Tasmania should be denied the federal $120 million for dedicated regional development opportunities."

Economic Development Minister David O'Byrne said Cabinet was working hard to protect as many forestry jobs as possible but warned there was no easy solution.

"We understand there is some concern over the future of their industry but they can rest assured that the Tasmanian government is doing all that we can to ensure that there can be a sustainable forestry industry for generations to come," he said.

A protest against Gunns' proposed Tamar Valley pulp mill will be held at the Long Reach mill site today at noon. Pulp the Mill, Still Wild Still Threatened and the new Code Green group will take part.