General Motors and Unifor have reached a tentative agreement that would pump C$144 million into the automaker's Oshawa, Ontario assembly plant to build next-generation heavy-duty GMC Sierra pickups, while pledging not to immediately close or sell its idled second Ontario facility in Ingersoll. The deal covers 4,600 union members in Ontario and now heads to a ratification vote members will hold this Saturday and Sunday.
The C$144 million investment, equal to roughly $104 million USD, would make Oshawa the only assembly plant in North America capable of building both light-duty and heavy-duty Chevrolet Silverado pickups on a single production line, according to Reuters. Adding heavy-duty GMC Sierra assembly to that same line would extend that flexibility to GM's GMC brand, giving the plant a broader lineup of full-size trucks to build as demand shifts. Reuters reported the deal from Montreal, with reporting from Allison Lampert and editing from Rod Nickel.
Unifor and GM's Canadian division declined to comment ahead of the ratification vote, per the same report. The union did issue a bargaining report about the tentative agreement, though it has not detailed every term publicly before members vote.
Ingersoll Plant Gets a Reprieve, Not a Restart
GM's CAMI Assembly plant in Ingersoll was idled in late 2025 after the automaker ended production of Chevrolet BrightDrop electric delivery vans amid weak demand, leaving roughly 1,050 Unifor members — about 30% of GM's Canadian unionized workforce — on layoff, according to CBT News. The tentative deal does not restart production there, but it does commit GM to holding off on closing or selling the plant outright, addressing one of the union's central priorities heading into bargaining.
The Oshawa investment builds on a pattern of GM capital spending in Ontario. In February, GM Canada announced a separate C$63 million investment in Oshawa to upgrade stamping operations for next-generation gas-powered full-size pickups, bringing the automaker's total capital commitments to the plant to C$1.5 billion since 2020, per Canadian Auto Dealer. Oshawa had already absorbed workforce cuts earlier this year, when GM eliminated the plant's third production shift, resulting in 500 layoffs as the facility retooled for next-generation vehicle platforms, according to BNN Bloomberg.
Under the same Unifor master agreement, GM's St. Catharines Propulsion Plant has been designated to build the company's next-generation V8 internal combustion engines for high-demand truck and SUV lines, feeding assembly plants across North America. That arrangement underscores how Oshawa, Ingersoll and St. Catharines function together as an interconnected manufacturing network rather than standalone sites.
Pattern Bargaining Traces Back to Ford
The GM terms echo a benchmark agreement Unifor ratified with Ford Motor Company of Canada in July, which set the pattern for this round of talks. That Ford deal secured a 9% general wage increase over three years, a C$10,000 ratification bonus for full-time workers, and C$1.25 billion in Canadian manufacturing investments, according to Just Auto. Unifor represents more than 41,000 autoworkers across Canada in assembly, powertrain and auto parts operations, and the union plans to move directly into contract talks with Stellantis once the GM ratification process wraps up.
That next round of negotiations carries its own weight. Unifor revealed on August 14 that Stellantis was actively considering closing and selling its Brampton, Ontario assembly plant, where 2,200 union workers have been on layoff since 2023 after Stellantis shifted planned Jeep Compass production to the United States. Under Unifor's collective agreement, any plant closure or sale requires at least one year's written notice, but the prospect illustrates how exposed Ontario's auto sector remains as automakers weigh moving production south.
Tariffs Cloud the Investment Picture
GM's willingness to commit fresh capital to Ontario comes as trade tensions between Washington and Ottawa remain unresolved. U.S. tariffs on Canadian-produced vehicles currently sit at 25%, and President Trump has said he will raise tariffs on all Canadian cars, trucks, automotive parts and steel to 50% starting January 1, 2027. Trump also signed presidential proclamations in July imposing 50% tariffs on a broad selection of other Canadian goods, compounding the existing auto duties, according to Blake, Cassels & Graydon LLP.
Talks between the U.S. and Canada aimed at reducing those tariffs on Canadian-built vehicles broke down last week over unresolved issues, including whether to cut duties on medium- and heavy-duty vehicles. Canada has said it cannot accept a U.S. trade deal unless it ensures the survival of a robust Canadian auto assembly and parts industry, per Reuters. The Canadian dollar was trading at C$1.3901 per U.S. dollar at the time of the report.
Adding to the uncertainty, the United States formally declined to extend the Canada-United States-Mexico Agreement for another 16-year term during the pact's mandatory six-year review on July 1. Current provisions remain in force through 2036, but the decision triggers annual trilateral reviews that will keep continental automotive trade rules subject to ongoing renegotiation, according to Baker Donelson.
For now, the tentative GM-Unifor agreement gives Ontario autoworkers a concrete win: new truck assembly work in Oshawa and a stay of execution for Ingersoll. Whether that investment holds up over the life of the three-year contract may depend less on the shop floor than on decisions made in Washington over the coming months.
