Several First Nations, municipalities and environmental groups that are opposed to the approval process of the Trans Mountain pipeline expansion in British Columbia will be arguing their position in the Federal Court of Appeal over the next two weeks.

The hearing beginning Monday in Vancouver consolidates numerous lawsuits filed by seven First Nations applicants, the cities of Burnaby and Vancouver, the Raincoast Conservation Foundation and the Living Oceans Society, which claim the National Energy Board's approval process was flawed and First Nations weren't adequately consulted.

The $7.4-billion project proposed by Trans Mountain, a subsidiary of Kinder Morgan Canada, would triple the capacity of the Alberta-to-B.C. pipeline and increase tanker traffic off the West Coast sevenfold. It received approvals from the federal government last year.

Eugene Kung, an environmental lawyer with West Coast Environmental Law who has been involved in the case, said those fighting the pipeline want to see the federal government's approval of the project overturned.

"At the very minimum that process needs to be redone in a way that takes into account in a very real way the risks and looks more deeply at the perceived need of the project," Kung said.

Environmental lawyer Eugene Kung, right, and Rueben George — project manager for the Tsleil-Waututh Nation Sacred Trust Initiative — are seen in Vancouver in May 2016. (Darryl Dyck/Canadian Press)

Specific concerns with the project range from a lack of consideration of alternatives to the project, the implications for endangered species including southern resident orca whales, and adequate accommodations for each individual First Nation whose territory is affected by the pipeline.

First Nations allege the project infringes on their land claim rights and title and the government failed to meet its fiduciary duty to thoroughly consult affected communities.

"For the federal cabinet decision to stand, they will essentially have to win on every single one of those issues," Kung said.

'Every tool in the tool box'

The Alberta and B.C. governments have been granted intervener status in the case, but will not be permitted to bring new information to the hearing.

The hearing has pitted the provinces against each other, with Alberta Premier Rachel Notley previously saying her government has taken measures to reduce the environmental effects of the oil and gas industry and that it's important for the country that the project go forward.

While B.C.'s former Liberal government gave environmental certificates to the project earlier this year, the province's new NDP Premier John Horgan said during his election campaign last spring he would use "every tool in the toolbox" to stop the expansion.

British Columbia Premier John Horgan said during his election campaign last spring he would use 'every tool in the toolbox' to stop the pipeline expansion. (Darryl Dyck/Canadian Press)

But Kung said with the provinces unable to present new information at the hearing, it's unclear whether either party could have a significant influence on the case.

"Interveners are invited dinner guests but they're not allowed to bring any additional food to the table. They can just discuss the food that's already on the table," he said.

What could hold greater weight in the case, Kung said, is a recent Federal Court of Appeal decision that the federal government failed to assess the effects of Kinder Morgan's pipeline easement on the Coldwater Indian Band.

The ruling issued last week regarding the existing pipeline that was agreed upon 60 years ago says the government had a continuing duty to protect the band's interests on its reserve from an exploitive bargain.

Pipes are seen at the Kinder Morgan Trans Mountain facility in Edmonton in April. The $7.4 billion project would triple the capacity of the Alberta-to-B.C. pipeline and increase tanker traffic off the West Coast sevenfold. (Jonathan Hayward/Canadian Press)

The Coldwater band is among the applicants in the upcoming hearings against the pipeline expansion.

Kung said the ruling adds additional uncertainty to the future of the project as it puts more weight on the federal government to not only consult First Nations but also to make decisions with their interests in mind.

Construction of the project was expected to begin this fall.

Kinder Morgan Canada said last month it had selected or signed agreements with six firms that have experience in building pipelines and major infrastructure projects in both provinces.