Overview
- Guilbeault announced on May 27 that he will resign his seat later this summer and will remain a Liberal MP until the House of Commons rises for the summer recess.
- He cited the Carney government’s dismantling or weakening of Trudeau-era measures — including the consumer carbon price, the zero-emission vehicle standard, the oil-and-gas emissions cap and clean electricity rules — as the reason for his departure.
- Prime Minister Mark Carney publicly thanked Guilbeault for his service, and Guilbeault told colleagues at a Wednesday caucus meeting that he is “at peace” with his decision.
- The move slightly narrows the Liberals’ thin majority and guarantees a future by-election in Guilbeault’s Montreal riding while highlighting private unease among roughly a dozen Liberal MPs over the federal–Alberta memorandum of understanding.
- Guilbeault leaves as one of Canada’s best-known environmental figures after co-founding Équiterre and serving as environment minister where he helped enact emissions limits and biodiversity protections, and his exit signals a shift from inside-government change to outside pressure that could shape Canada’s climate debate and policy direction.