The federal government says it will intervene in the B.C. provincial government's Trans Mountain pipeline court reference action that will decide whether the province can restrict any increase in the amount of diluted bitumen that moves across its border.

"We are confident in Parliament's jurisdiction and will intervene on the question in order to defend our clear jurisdiction over interprovincial pipelines," Justice Minister Jody Wilson-Raybould said in a statement.

B.C. Premier John Horgan announced last month that his province's highest court would be asked to determine if B.C. has the right to seek permits from companies that want to increase the amount of bitumen being shipped to the West Coast.

The federal government will now be in a position to make arguments and present evidence in the case.

The federal move is the latest development in the ongoing standoff between the B.C. government — which wants to block the expansion of the Trans Mountain pipeline from the Alberta oilsands to the B.C. coast — and the Alberta and federal governments, which back the expansion.

The court case essentially is asking the B.C. Court of Appeal if the province has the jurisdiction to implement a law it has drafted that would amend the province's Environmental Protection Act with the new regulations.

The draft legislation says companies seeking to bring more diluted bitumen through B.C. would need a permit from the province.

Targeting the pipeline

The new regulations, should they be deemed legal, would apply only to increases in the flow of bitumen into B.C., not to existing shipment levels.

Alberta Premier Rachel Notley has called the move another attempt by B.C. to delay or scuttle Kinder Morgan's pipeline expansion.

"If bitumen was so hazardous, why would we only be looking at the incremental bitumen in the new pipeline?" she said last month. "This isn't about the environment. This is about the new pipeline, which is well beyond [B.C.'s] authority."

After B.C. announced it was going to the province's highest court, the Canadian Association of Petroleum Producers described the action as little more than a stalling tactic designed to bog down the Trans Mountain pipeline expansion.

"The government of Canada now needs to exercise its constitutional authority and act in Canada's best interests to move the project forward without further legal or political delays from the B.C. government, or risk hurting the national economy and the livelihoods of thousands of middle-class Canadians," the organization said in a news release.