To shouts of "Line 9, shut it down," demonstrators derailed a National Energy Board hearing in Toronto this afternoon that was examining a controversial proposal by energy company Enbridge about one of its key petroleum pipelines.

Protesters, many gathered under the banner of the Idle No More movement, first milled outside the Metro Toronto Convention Centre to rally against the Line 9 pipeline and to show solidarity with demonstrations at New Brunswick's Elsipogtog First Nation against a shale-gas project.

"We stand with Elsipogtog,  we stand with the warriors and we stand with the people," said Nina Wilson, one of the founders of the Idle No More movement.

Line 9 NEB hearings protests

Demonstrators outside the Metro Toronto Convention Centre were rallying in opposition to Enbridge's Line 9 and in solidarity with protests in New Brunswick against shale-gas exploration. (CBC)

"Our water, our greatest medicine that we’ve ever had, is under direct attack.… You will not survive without clean water, so that is what this is about."

The National Energy Board was hearing statements inside the convention centre about Enbridge's proposal when Toronto police blocked the protesters from entering the public hearings. They were eventually allowed in slowly, after the NEB determined that there were enough seats.  

"We only have so many seats in the hearing room. So for fire safety, life safety, we have to make sure that we don’t exceed room capacity," said Lee Williams, an NEB security adviser.

After an anti-Line 9 deputant completed her official submissions to the NEB panellists, the demonstrators began chanting and moving up to the front of the room toward the panel.

"No Line 9, no Line 9," they yelled. "Listen to the people, regulators!"

There was a brief scuffle with security. Then the NEB panel members were escorted by security and police out of the room, as was an Enbridge representative.  

Protesters stayed and chanted until they were asked to leave by police.  

Calgary-based Enbridge wants to reverse Line 9 to flow from southern Ontario to Montreal, and to increase its capacity to move 300,000 barrels of crude oil per day, up from the current 240,000 barrels. Enbridge has said what will flow through the line will not be a raw product from Alberta's oilsands, although there will be a mix of light crude and processed oilsands bitumen.

Opponents say the proposal puts First Nations communities at risk, threatens water supplies and could endanger vulnerable species in ecologically sensitive areas.

Enbridge has experienced several devastating spills on its pipelines, including one in Michigan that leaked 3.3 million litres of oil into the Kalamazoo River and has already cost the company more than $1 billion. The U.S. Environmental Protection Agency believes there is at least 684,000 litres of bitumen still in the river.