COMMUNIST Party of Canada leader Liz Rowley warned of environmental disaster after Prime Minister Justin Trudeau agreed to the construction of a much criticised polluting pipeline, the latest of a series of promises broken since the Liberal leader came to power in 2015.

Ms Rowley said that building the Trans Mountain pipeline, which will transport heavy tar sands oil from Alberta to a port on the British Columbia coast, would add thousands of tons to the annual emissions of greenhouse gases, which are responsible for global warming.

But she told US news site People’s World that there would be a fight to stop it, with First Nations people, environmentalists, the British Columbia government and the Communist Party all stepping up to protest.

The pipeline was finally approved earlier this week, with Mr Trudeau’s party arguing that the project was necessary to break Canada’s dependence on US oil.

The government was footing the bill for the pipeline to “remove any political risk associated with the project,” according to Mr Trudeau. However, he plans to sell it to the private sector as soon as possible.

“We have no intention of being the long-term operator of the pipeline,” he confirmed yesterday, promising work would start later this year.

Mr Trudeau insists profits from the sale will be invested in “green projects.”

British Columbia Green Party leader Andrew Weaver said he was concerned about the potential for civil disobedience. “As a political party, you will not see me standing up and condoning or participating in civil disobedience. I don’t believe as a lawmaker it behoves me as such a person to actually break said law,” he said.

“However, I understand that in times of strife, people find different ways of expressing themselves. I’m very worried about how this is going to end up.”

But Ms Rowley said: “If you don’t fight, you’re going to lose everything.”

She called for a “unity of all progressive forces” on the issue, pointing out that the pipeline was just the latest in a string of broken promises by Mr Trudeau, who has let down women, workers, First Nations and environmentalists.

She warned that the Liberals will be held to account in the forthcoming general election. “There’s been massive opposition to the government’s decision, and it’ll hit them in the election this fall. There is really wide public sentiment that it’s a bad idea. The pipeline is the big issue” in the election, she said. “Indigenous people have had big protests, and there will be more.”