An appellate verdict last week blocked the British Columbia (BC) government’s campaign to stop the Trans Mountain Pipeline expansion (TMX) project by enacting provincial control over oil deliveries through the planned facilities.

A five-judge panel in the BC Court of Appeal ruled Friday that Canada’s constitutional division of powers prevents the province’s New Democratic Party (NDP) regime from usurping federal jurisdiction over a national enterprise.

The failed NDP maneuver was a legislative proposal, billed as environmental protection against oil spills, for provincial power to inflict penalties of up to C$400,000 ($300,000) and six months in jail for increasing bitumen shipments via TMX.

BC Premier John Horgan, who has pledged to use every tool available to stop TMX, said further legal appeals are likely. His options include taking the fight against the pipeline project up to the Supreme Court of Canada.

The BC appeal court verdict paves the way for federal cabinet approval, scheduled for June 18, of the C$9-billion TMX expansion across 987 kilometers (592 miles) of Alberta and BC from Edmonton to a Pacific tanker dock near Vancouver in Burnaby.

The Liberal government in Ottawa bought Trans Mountain for C$4.5 billion ($3.4 billion) from Kinder Morgan Canada last year after environmental, native and BC government protests fought the pipeline expansion to a standstill.

The scheduled June decision would be the second one on the project, following extra regulatory reviews to correct flaws that the Canadian Federal Court of Appeal identified in the first approvals by the National Energy Board and cabinet.

The TMX project stands out as a growth enabler for Canada’s top natural gas user, Alberta thermal oilsands production. Capacity on Trans Mountain would nearly triple to 890,000 b/d.

The BC appellate verdict dismissed the opposition action devised by Horgan’s NDP regime as “an immediate and existential threat to a federal undertaking that is being expanded specifically to increase the amount of oil being transported through BC.”

The unanimous ruling written by Justice Mary Newbury said, “it is simply not practical — or appropriate in terms of constitutional law — for different laws and regulations to apply to an interprovincial pipeline, or railway or communications infrastructure, every time it crosses a border.”

Newbury observed, “There is in place a complex web of federal statutes and regulations that apply to all aspects of interprovincial pipelines, including environmental assessment, operational oversight, spill and accident responses, and financial liability and compensation for harm done by spills. The ”polluter pays’ principle is clearly an important part of these laws.”

The judge added, “The approval process is still continuing. The minimization of environmental harm associated with interprovincial undertakings is a key component of the federal matter.”