First Nations and environmental groups are planning to file three lawsuits Thursday against the federal government and Malaysian state-owned oil firm Petronas in an attempt to stop a liquefied natural gas project on British Columbia's northern coast.

The $36-billion Pacific NorthWest LNG project which includes a pipeline and terminal proposed for Lelu Island, near Prince Rupert, received conditional approval from the federal government last month.

Chief Negotiator of the Gitanyow Hereditary Chiefs Glen Williams says the project could have a severe impact on communities in the area by destroying habitat for local salmon stock.

Williams says Gitanyow Hereditary Chiefs and the Gitwilgyoots Tribe want the Federal Court to declare that proper consultation with First Nations did not occur, and subsequently cancel approval for the project.

He says he hopes a Federal Court of Appeal judgment that blocked the Enbridge Northern Gateway pipeline earlier this year because First Nations weren't properly consulted will set a precedent for success in this suit.

SkeenaWild Conservation Trust spokesman Greg Knox says another lawsuit by his organization argues environmental assessment data provided by Petronas are incorrect and unfounded.

A spokesperson for Pacific NorthWest LNG declined to comment on the lawsuits Wednesday.