Treaty 3’s grand chief is warning Ottawa it cannot “legislate itself out of its constitutional duties” after the federal government moved to designate a proposed nuclear waste repository in northwestern Ontario as a national interest project.

In a letter to Prime Minister Mark Carney published Monday, Ogichidaa Francis Kavanaugh says he is “very committed” to working with the Major Projects Office on this project, but warned against designation.

The Building Canada Act (BCA) designation would allow the Carney government to expedite parts of the review process, though the act cannot influence the independent Canadian Nuclear Safety Commission assessment.

“The [deep geological repository, DGR] is imposing an enormous ask on the Nation and Treaty 3 First Nations… Canada is now imposing even more by initiating the BCA process,” reads part of the letter.

Kavanaugh said designating the project would create regulatory uncertainty, increase the risk of errors and could lead to poor outcomes. 

“Based on the uniqueness, size, and temporal scale of the DGR, I have no appetite for cutting any corners in assessing the environmental consequences and impacts to inherent and Treaty #3 rights.” 

The letter points to a significant breakdown in the relationship between Treaty 3 leadership and the Nuclear Waste Management Organization (NWMO), the project’s proponent, since the December 2024 site selection decision.

Kavanaugh alleges his organization recently requested more time to finish “harmonization work” for a joint review process under Anishnaabe and Canadian laws, and that the federal government responded by announcing plans to designate the project under the act.

He warned Ottawa should ‘change course immediately’ and threatened legal action.

Wabigoon Lake First Nation is a member of the Grand Council of Treaty 3, and one of the two host communities for the nuclear waste project along with the township of Ignace. 

Jacob Gorenkoff, CEO and founder of Homeward, the public affairs firm representing the First Nation in Ottawa, tells iPolitics the Anishnaabe community is generally supportive of designating the project. 

“It’s the best possible path to ensure Wabigoon has a voice in everything that’s to come with the project,” he said. 

“The Major Projects Office opens up a lot of doors for us to be able to speak with the federal government, it would be much more difficult without that process.” 

READ MORE: Ottawa kicks off process to designate 3 projects of national interest, including nuclear waste

When the federal government launched the designation process last week, it said it would lead consultations throughout the summer, with official designations to potentially follow in the fall. 

At a technical briefing for reporters before the announcement, iPolitics asked a member of the Major Projects Office if the government would continue to pursue designation of the nuclear waste project should Treaty 3 “clearly and firmly” oppose it. 

The spokesperson responded that the government intends on having a consultation with all potentially impacted groups to better understand views and perspectives on the project, with the goal of informing a final recommendation to the Carney government. 

Ottawa has singled out the nuclear waste project as a priority, as its completion would pave the way for more nuclear power as Canada struggles with a surge in anticipated electricity demand.

The NWMO’s search for a permanent home for Canada’s used nuclear fuel has been decades in the making.

The formal regulatory process began in January 2026 with the submission of the Initial Project Description to the Impact Assessment Agency of Canada, before the federal government referred the project to the Major Projects Office on June 24, 2026.