Hundreds of government-employed firefighters, who work in state forests and national parks, are often paid less than their counterparts in other fire agencies and are denied equal levels of death and disability insurance.

They have accused the state government of "disregard and even contempt" for the men and women who risk their lives in emergencies and work year-round conducting bushfire-prevention operations.

Over coming weeks, fire workers from the Department of Environment, Land, Water and Planning will refuse to carry out planned fuel-reduction burns across Victoria, as the stoush over a new workplace agreement drags on.

The dispute has become yet another industrial headache for Labor, which has faced weeks of public transport chaos during strikes by Metro and Yarra Trams workers in Melbourne..

Australian Workers Union state secretary Ben Davis said the firefighters' decision to launch wide-ranging industrial action, including bans on planned burning, came after lengthy attempts to advance negotiations.

"This government appears too lethargic to respond to issues that are taken very seriously by our members and the people of regional Victoria in particular," Mr Davis said.

"It is simply reprehensible that the matters these negotiations raise have not been made top priority, particularly when we are told we are facing an above-normal fire danger in the coming season."

Josh Hopwood, a forest firefighter for more than a decade, said the dispute boiled down to a matter of respect for important work that protects the state.

"We're sometimes referred to as the 'ghosts of the bush'," he said.

"In the news all you see is the CFA, and a lot of our work goes unnoticed because it happens 30 kilometres away from towns.

"But sometimes it's worse out there. People said last year we didn't have a bad fire season, but in Mansfield we had so many multiple lightening strikes. Our district was one of the busiest in the entire state."

Mr Hopwood, 30, said department fire crews carry out dangerous work for 10 months of the year, including bushfire-prevention operations and front-line fire fights, in addition to being deployed to interstate natural disasters..

Mr Davis said it "defied belief" that that forest firefighters' work was not classed as an emergency service "given their history of defending the state at the worst of times", including Black Saturday.

Departmental fire workers include firefighters, maintenance teams, look-out observers and expert "rappel crews", who abseil out of helicopters to battle blazes in otherwise inaccessible forest areas.

About 95 per cent of the bushfires that occur in Victoria take place on public land where forest firefighters are the first to respond, according the union.

The Victorian government said other workers could be deployed to help carry out planned burns and the seasonal bushfire-prevention program would continue.

Environment Minister Lisa Neville said she encouraged the union and the department to work closely and reach a resolution.

"Our fire staff do an amazing job and we value the important contribution they make," Ms Neville said.

Opposition Leader Matthew Guy said the threat of industrial action was evidence the union was running the government. He said the union movement was treating Victorians with contempt.

"The government's got little sway over them," he said.

Mr Guy said planned burning targets must be met, and called for the union and the government to "sort out their differences."

With Benjamin Preiss