The longtime climate activist is expected to address the House of Commons May 27 to inform his constituents that he will be leaving as their MP once Parliament adjourns for the summer, according to the reports.
The reports said that the Prime Minister’s Office is aware of Guilbeault’s plan to resign and added that although the Quebec MP has clashed with Carney on climate change policies in the past, his speech is not expected to bring up these topics of disagreement.
In addition to previously serving in various cabinet roles as the Minister of Environment and Climate Change, Minister of Canadian Identity and Culture and Parks Canada, and Minister responsible for Official Languages, as well as briefly serving as Quebec Lieutenant, Guiltbeault is also a member of the House Committee on Foreign Affairs and International Development.
“When I entered politics, it was because I had a deep conviction that I could make a difference in fighting climate change and protecting our environment,” he said in a Nov. 27 statement. “My commitment to leaving a better world for the future of our children and our planet remains unchanged.”
Industry Minister Mélanie Joly has stated her support for the MOU, saying that despite being part of “the environmentalist part of the Liberal Party and cabinet,” she considers the MOU to be the right move.
In the past year, the Carney government has eliminated the consumer carbon tax, pledged to replace the federal electric vehicle sales mandate with stricter emission regulations, signalled it is open to abandoning the proposed oil and gas emissions cap, and backed away from earlier Liberal pledges to phase out fossil fuel tax credits.
Alberta Premier Danielle Smith has praised the recent agreements on a new oil pipeline and other measures with the federal government. The province plans to put its proposal for the Alberta–B.C. pipeline before the Major Projects Office by July 1, and Smith has said that the project could break ground by September of next year.
Many of the policies being walked back by Carney’s government were crafted and backed by Guilbeault during his years as Minister of Environment and Climate Change. Prior to his election as an MP in 2019, Guilbeault started an environmental organization called Équiterre focused on climate change policies, and worked with Greenpeace.
He gained public attention in 2001 after climbing the CN Tower in Toronto and dropping a large banner reading “Canada and Bush Climate Killers,” accusing then-U.S. President George W. Bush and the administration of then-Prime Minister Jean Chrétien of worsening climate change by not ratifying the Kyoto Protocol, an international accord with the stated aim of curbing greenhouse gas emissions. Canada ratified it in 2002 and later withdrew in 2011.
Guilbeault’s possible plans after resigning as MP this summer have not been disclosed.
While Guilbeault’s constituency of Laurier—Sainte-Marie was recently a relatively safe seat for Liberals, it has historically also been competitive for both the NDP and Bloc Québécois. Guilbeault won the riding in the 2025 federal election by 52 percent, with a large margin of victory over the runner-up NDP candidate.
