VANCOUVER -- A First Nation in North Vancouver has mounted a legal challenge that it says could send the Trans Mountain pipeline expansion "back to the drawing board" if successful.

Lawyers for the Tsleil-Waututh Nation are asking the Federal Court of Appeal to stop the National Energy Board's review of the $5.4-billion project, which they say began without their client being consulted by the federal government.

"What we've asked the court to do is to recognize the flaws in the starting of the process, the process itself, the legal errors that the NEB has made and, really, to stop the process and send it back to the drawing board," said Eugene Kung, staff counsel with West Coast Environmental Law.

The Trans Mountain pipeline currently ships 300,000 barrels a day of petroleum products from Alberta to the West Coast. Its owner, Kinder Morgan, aims to nearly triple its capacity, enabling oilsands crude to be shipped by tanker to Asia.

The Tsleil-Waututh are among various groups opposed to the project, citing environmental and public health risks and little benefit to the economy.

Rueben George, project manager with the Tsleil-Waututh's Sacred Trust Initiative, said the outgoing Conservative government created a "catastrophic mess" with changes it made to environmental oversight and he's optimistic things will change under the new Liberal majority government.

Many critics have slammed the regulatory review process for being skewed in favour of industry and for not taking into account the pipeline's role in enabling more oilsands development -- and the increased carbon emissions that would result.

The NEB postponed hearings in August after striking economic evidence prepared by a consultant who was to begin working for the regulator starting this month. Steven Kelly won't be involved in the Trans Mountain assessment, but the NEB nonetheless said it wanted to ensure no questions were raised about the review's integrity.

Kinder Morgan has said the project underwent "unprecedented" scrutiny inside and outside the formal review process and would add $18 billion to Canada's gross domestic product over 20 years.

"Trans Mountain deeply respects aboriginal rights and title in Canada and we acknowledge the Crown's responsibility to consult with representatives of the First Nations. For more than three years we have been engaging in meaningful consultation and to date Trans Mountain has consulted with approximately 133 Aboriginal and First Nations Groups," the company said in a statement.

"Like the Tsleil-Waututh, Trans Mountain appreciates the need for a healthy Salish Sea, and we are committed to safe and environmentally responsible operations. As always Trans Mountain stands by our commitment to engage with First Nations and invites Tsleil-Waututh Nation to come to the table and engage in clear productive conversation."

George said what's needed is nation-to-nation consultation.

"Kinder Morgan's a company. Who should consult with us is Canada. They have no business talking to us. It's Canada that has to talk with us," he said.

NEB spokeswoman Tara O'Donovan declined to comment on the specifics of the court case.

"Our decisions are subject to independent and impartial judicial oversight. That's usually either through the Federal Court of Appeal or the Supreme Court of Canada. We are bound to act in accordance with the court's decisions," she said.

The Tsleil-Waututh was granted leave to appeal in July, so that's already been factored into the review's hearing schedule, said O'Donovan.

The panel will hear Trans Mountain's oral summary arguments in Calgary on Dec. 17, with interveners having their turn in the new year.