About 4,300 unionized workers began striking at three GM plants in Canada on October 10 as the automaker continues to struggle with work stoppages in the U.S. as well.

According to the Canadian Broadcasting Corporation, the walkout came after the Canadian union Unifor, which represents 310,000 workers across several industries, said that GM was “stubbornly refusing” to match the three-year deal the labor union had previously reached with Ford Motor, which promised a wage increase of up to 25%.

The union said it will be striking against GM’s Oshawa assembly complex, its Woodstock parts distribution center and its St. Catherines powertrain plant. GM could end up facing production delays because workers at the St. Catherines plant make engines and car components for numerous vehicles, including powertrains for the Chevrolet Equinox and Corvette.

"The decision to strike was not taken lightly," Unifor said in a statement. "After working throughout the Thanksgiving weekend and into the final hours before the deadline, General Motors made it clear that they would not agree to meet the conditions of the pattern agreement."

Unifor, which represents 18,000 workers at Canadian facilities servicing Detroit Three automakers, is looking for more benefits for part-time workers who are looking for full-time employment, improvements to the employee pension plan and greater support for retired workers.