Final approval of the costliest, most contested version of a proposed overseas export pipeline and Pacific Coast tanker port for Alberta oil has been suspended by Canada’s Federal Court of Appeal.

A two-member majority of a three-judge appellate panel ruled Thursday that the former Conservative cabinet in Ottawa fell short of fulfilling Canadian constitutional duty to consult and accommodate aboriginal groups affected by large projects.

The court majority said a second run must be taken at obeying native rights aspects of a legislated requirement for the federal cabinet to ratify the approval decision recommended by a joint review panel of the National Energy Board (NEB) and Canadian Environmental Assessment Agency (CEAA).

The appellate ruling sets back Enbridge Inc.’s C$8 billion (US$6.2 billion) Northern Gateway proposal for an entirely new oilsands export conduit from the Alberta capital of Edmonton to the northern Pacific coast port of Kitimat (see Daily GPI, Dec. 20, 2013).

The court decision does not affect Kinder Morgan Canada’s less contentious US$5.5 billion alternative of tripling capacity, to about 900,000 barrels per day, on the half-century-old Trans Mountain Pipeline from Edmonton to an established tanker dock at Vancouver (see Daily GPI, May 20, 2016). Both rival projects would add about 600,000 b/d to oilsands exports from Alberta thermal extraction sites, which are Canada’s top consumers of natural gas.

In the Northern Gateway case, the appellate judges upheld the NEB-CEAA’s years-long regulatory review and its book-length approval recommendation that included more than 200 safety, engineering, environmental and community acceptance conditions.

But the court ruled that cabinet representatives for a special constitutional “independent duty to consult” aboriginal groups let down the process by holding only a token round of hasty meetings that dealt superficially with native concerns in a generic fashion. Aboriginal groups do not have veto powers on projects but do have rights to expect focused attention to their various regional and territorial concerns, the judges said.

By the standards of Enbridge’s epic two decades of work on Northern Gateway, fulfilling the government’s separate aboriginal consultation obligations is “a matter that, if well-organized and well-executed, need not take long,” the court said. The job could be done in about four months, the judges said.

But the ruling puts Prime Minister Justin Trudeau in a political hot seat. During his Liberal party’s successful campaign to oust Stephen Harper’s Conservatives from power last fall, he went on record as siding with native and environmental protesters to put a stop to Northern Gateway.

Aboriginal factions that have stayed out of project participation agreements offered by Enbridge, and environmentalist resistance groups called on Trudeau to keep his word by leaving Northern Gateway in limbo. Enbridge vowed to continue advancing the project.

Trudeau did not take sides on Kinder Morgan Canada’s alternative export conduit, which was in its regulatory hearings stage during the federal election. A special tribunal, appointed by Trudeau’s cabinet, is currently holding elaborate independent consultations with native and public groups on ratifying a 157-condition Trans Mountain Pipeline expansion approval recommended this spring by a NEB-CEAA panel.