The B.C. Supreme court has ruled that the province "has breached the honour of the Crown by failing to consult" with the Gitga'at and other Coastal First Nations on the Enbridge Northern Gateway pipeline.

The court challenge — one of many on the controversial proposed pipeline — stemmed from the B.C. government's agreement with Ottawa to hold a single environmental assessment process, under the National Energy Board, rather than parallel federal and provincial reviews.

In 2014, the federal government approved the controversial pipeline that would bring heavy Alberta oil to B.C.'s north coast, for international shipment by tanker.

But First Nations opponents of the pipeline argued the province wasn't living up to its own duty to consult with them, and today, the court found in their favour.

"This is a huge victory that affirms the provincial government's duty to consult with and accommodate First Nations and to exercise its decision-making power on major projects," said Arnold Clifton, Chief Councillor of the Gitga'at First Nation, in a statement.

B.C. government 'playing politics'

Though the governing B.C. Liberals had agreed to the streamlined process — and even trumpeted it as something that would reduce "byzantine bureaucratic practices" and help create jobs, the province had also formally opposed the pipeline.

First Nations won a major battle Wednesday in their fight against the Northern Gateway pipeline when the B.C. Supreme Court rules they had not been adequately consulted. (CBC)

The B.C. government was an intervenor in the National Energy Board's joint review process, speaking against the proposal, because it didn't meet the five conditions set out by B.C. for any heavy oil pipeline.

The chief problem, said the government, was there wouldn't be "world-class spill response capability" in place, despite the company's claims, according to the judgment.

Art Sterritt, a Gitga'at member and vocal opponent of the pipeline, said the B.C. government was "playing a bit of politics" by handing over its power at the environmental assessment stage, then opposing the project.

"They were saying [to the federal government] yeah, we're opposed, but you go ahead and make you're decision, we'll live with it," said Sterritt.

Sterritt said the court ruling means the B.C. government would have to start from scratch on consulting with affected First Nations for its own review.

"You're talking about a whole new review process here," said Sterritt. "I'm not sure that Northern Gateway or anyone else would have the appetite for that."

But B.C. Attorney General Suzanne Anton said the judgment won't require restarting the pipeline approval process.

"What the court has said is we can rely on the process that was in front of the National Energy Board, but we do need to make our own independent provincial decision based on our own provincial legislation," she said.

Anton said the province hasn't yet decided on whether to appeal, and she is committed to fully consulting with First Nations.

Federal approval stands, says company

However, Northern Gateway says the federal decision stands, and its still working to meet the 209 conditions set out by the NEB, along with the B.C. government's conditions.

Jacqueline Lee-Tam wears face paint to simulate oil while attending a rally held to show opposition to the Enbridge Northern Gateway pipeline in Vancouver, B.C., on Tuesday June 17, 2014. (Darryl Dyck/Canadian Press)

"Approval of the project falls within federal jurisdiction and this decision from the B.C. Supreme Court does not change that approval or the project's environmental assessment," said Ivan Giesbrecht, communication manager for Northern Gateway, in a statement.

"Northern Gateway and the project proponents, including Aboriginal Equity Partners, remain committed to this essential Canadian infrastructure."

Ottawa's role in the fate of the project has also been in question following Justin Trudeau's Liberal win in October.

Trudeau has called for a moratorium on crude oil tanker traffic on B.C.'s north coast, which would block the main reason for the pipeline — to ship oil via tanker from Kitimat to Asian markets and elsewhere.

Northern Gateway has been undeterred by that plan, however.

B.C. Justice Minister Suzanne Anton has not yet commented on the court ruling.