Canada’s federal government will cover financial losses a pipeline builder might suffer if British Columbia’s provincial government continues to obstruct the Trans Mountain pipeline expansion said Bill Morneau, the country’s finance minister, on Wednesday.

Morneau also said that other investors would step in if Houston-based Kinder Morgan backs out of the expansion, which would triple the capacity of a line carrying oil from Alberta to a Pacific port.

Kinder Morgan has halted essential spending on the project and says it will cancel it altogether if the national and provincial governments cannot guarantee it. British Columbia’s leftist premier has objected to the plan on environmental grounds. The company set a 31 May deadline.

The line would allow Canada to diversify and increase exports to Asia, where it could command a higher price. Canada has the world’s third largest oil reserves but 99% of its exports now go to refiners in the US, where limits on pipeline and refinery capacity mean Canadian oil sells at a discount.

But the Trans Mountain pipeline expansion would dramatically increase the number of oil tankers traveling the shared waters between Canada and Washington state. Aboriginal leaders and environmentalists have pledged to do whatever necessary to thwart it, including chaining themselves to construction equipment. British Columbia’s new government has launched legal challenges.

“This is an exceptional situation,” Morneau said.

Morneau has been engaged in talks with Kinder Morgan.

“Discussions with Kinder Morgan continue – and we are striving to get to an agreement by the May 31 deadline,” he said.