Opponents are hoping to stop the multi-billion dollar Gateway Project in its tracks with a lawsuit claiming a key part of the transportation project runs through First Nations burial grounds.

The proposed South Fraser Perimeter Road would be an 80 km/hr 4-lane highway running adjacent to the Fraser River from Delta to Surrey, but artifacts and burial sites dating back 10,000 years lie along the banks of the Fraser River.

Lawyer Jay Straith obtained a leaked B.C. government report with a warning from its own archaeologists that say the planned route would disturb First Nations artifacts and grave sites along the river.

"If this was going through a Christian graveyard, a Jewish graveyard, an Islamic graveyard, all hell would be breaking loose. It's going through a First Nations graveyard that goes back thousands of years, and they seem to say, 'It's not an issue.'"

Straith is now suing on behalf of Tsawwassen band member Bertha Williams and William Burnstick from the Cree and Sioux First Nations.

The sensitive area lies near Glenrose Cannery just east of the Alex Fraser Bridge in Surrey, where crews have already begun construction.

"They're completely aware what they're doing and they're doing it anyways," Burnstick said at a press conference.

Planners say the new route will reduce east-west travel times, particularly for heavy trucks, and improve the quality of life for residents and local businesses.

The B.C. Transportation Ministry told CTV News it can't comment on the lawsuit because the matter is before the court.

With a report from CTV British Columbia's Peter Grainger.