General Motors’ (GM) (NYSE:GM) decision to cut a third shift at its Oshawa, Ontario, assembly plant this fall has ignited a political and labor firestorm in Canada, with hundreds of workers impacted.
Unifor, the country’s largest private sector union, issued an urgent call for action this past Friday (May 2) after GM confirmed it will be transitioning the plant to a two-shift operation. The automaker attributed the decision to evolving market conditions, including the 25 percent tariff the US imposed on Canadian-made vehicles in March.
GM spokesperson Marie Binette acknowledged in an email cited by CBC that the restructuring will “impact approximately 700 workers,” though she stopped short of calling the job losses layoffs.
“We are committed to supporting employees through the transition,” she said.
Unifor sees the move as a betrayal of Canadian workers and taxpayers, who helped revive the Oshawa facility after it was shuttered in 2019. The plant, which builds light- and heavy-duty Chevrolet Silverado pickup trucks for North America, reopened in 2021 with the help of significant public investment and union-backed production deals.
“GM Oshawa was reopened thanks to the hard work of our members and significant investments by the federal and provincial governments based on a promise to maintain good jobs and production,” said Chris Waugh, Unifor’s plant chairperson in Oshawa, in Friday’s release. “We will not sit idly by as that promise is eroded one shift at a time.”
Lana Payne, national president at Unifor, also weighed in, commenting, “We will not allow GM to barter Canadian jobs to gain Donald Trump’s favor. Cutting the third shift at Oshawa Assembly is a reckless decision that deals a direct blow to our members and threatens to ripple through the entire auto parts supplier network.”
The timing of GM’s announcement — just days before Canadian Prime Minister Mark Carney is set to meet Trump in Washington — has further fueled tensions between the company and Unifor.
“The Trump tariffs are designed to crush Canadian production,” Payne added.
“But GM doesn’t get a free pass to abandon its commitments, and the US doesn’t get to free ride in Canada. Canadians invested millions to revive this plant. Cutting jobs now has consequences. The company has six months to fix this.”
Mounting economic pressure
The layoffs in Oshawa are only the tip of the iceberg. Jeff Gray, president of Unifor Local 222, said another 1,500 jobs in the broader supply chain could be affected by the shift cut.
The union is urging the Canadian government to immediately review GM’s status under the country’s tariff remission framework — a system that grants tariff relief to companies on a conditional basis.
“If GM wants to sell in Canada, they need to build in Canada,” said Payne. “That message must be loud and clear.”
A recent report by Ontario’s Financial Accountability Office (FAO) estimates that US tariffs and Canada’s retaliatory measures could cost Ontario 68,100 jobs this year — most of them in manufacturing and related supply chains.
The FAO warns that job losses could balloon to nearly 138,000 by 2029 if trade tensions persist.
The same report predicts a “modest recession” in Ontario in 2025, with the province’s GDP growth cut in half and unemployment rising by 1.1 percent. Primary metal and motor vehicle parts industries are expected to be hit hardest.
Today’s news from GM is extremely tough for the workers in Oshawa and their families. These are hardworking people who have helped build Ontario’s auto industry. GM has reaffirmed its commitment to the Oshawa plant, which will continue building Ontario-made trucks for years to…
— Doug Ford (@fordnation) May 2, 2025
Ontario Premier Doug Ford also weighed in, calling the GM layoffs “extremely tough” in an X statement.
“These are hardworking people who have helped build Ontario’s auto industry,” Ford said. “We will continue doing everything we can to support a strong future for the facility and its workers.”
Under its collective agreement with Unifor, GM is obligated to meet with the union in the coming weeks to explore options to prevent or mitigate job losses in Oshawa. The union also plans to seek clarification on potential downstream effects, particularly at the St. Catharines powertrain plant, which supplies engines to Oshawa.
GM, which was Canada’s top-selling automaker in 2024 and retained that lead in Q1 2025, plans to refocus Oshawa production on Canadian truck sales, reducing exports to the US amid the tariff headwinds.
Securities Disclosure: I, Giann Liguid, hold no direct investment interest in any company mentioned in this article.