Environmentalists and anti-pipeline activists are gearing up for a mass sit-in at the B.C. legislature Monday, where many will be risking arrest to protest the embattled Northern Gateway project.

The planned demonstration is already being touted as the largest protest against the Alberta tar sands, oil pipelines and tanker traffic yet, though details about the event have so far been sparse and only time will tell how many people turn up.

“There’s not a lot I can say, besides the fact that it will be the largest act of civil disobedience against the tar sands in Canada," said organizer Eric Nordal.

Nevertheless, several thousand people are expected to make their voices heard on the lawn of the legislature in Victoria, even though the provincial government is not sitting.

Many say they are fed up, convinced that their grievances with the $6-billion Northern Gateway project – as well as the proposed twinning of the current Kinder Morgan pipeline – are not being heard by either the B.C. or federal government.

Zoe Blunt of the Forest Action Network said some protesters are bracing for a possible police crackdown at the demonstration.

“There will be hundreds of people actually risking arrest to show how upset they are about tankers and pipelines,” Blunt said.

Greenpeace says Hollywood stars such as Michael Moore, Ellen Page and Daryl Hannah have endorsed the protest, though there’s no confirmation they’ll be showing up on Monday.

High-profile B.C. activist Tzeporah Berman, who was arrested 20 years ago after participating in the Clayoquat Sound protests, which she helped to organize, has indicated she will appear.

“We have a federal government that wants to push these pipelines down our throats, no matter the cost to British Columbians,” Berman said. “They’re gutting our environmental laws; just yesterday they took water protection out of the Navigational Waters Act in order to push through these pipelines.”

Meanwhile, the National Energy Board’s joint review panel assessing the project continued Friday in Prince George.

Enbridge, the company behind the Northern Gateway proposal, admitted under questioning that it could not categorically guarantee there would never be an oil spill from its proposed pipeline.

A report released over the summer estimated B.C. would earn $8.9 billion in taxes from the pipeline by 2035 – or roughly eight per cent of the profits. The province would meanwhile assume 100 per cent of the marine risk and 58 per cent of the land-based risk of transporting bitumen from Alberta’s tar sands to Kitimat and abroad.

With a report from CTV British Columbia’s Peter Grainger