The offer from Chrysler’s parent company includes consolidating after-sales parts plants and increasing the number of supplemental workers the Jeep maker can use, the report said.

UAW president Shawn Fain said on Wednesday that Stellantis had proposed a 17.5% pay hike.

Union vice-president Rich Boyer criticised the proposal at a Friday rally in Detroit as “concessionary” and the result of concerns over the electrification transition, the report added.

The first simultaneous strike against the Detroit Three automakers, launched on Friday, has halted production at three plants, producing the Ford Bronco, Jeep Wrangler and Chevrolet Colorado, along with other popular models.

The union, which represents 146,000 US auto workers, has been asking for 40% pay raises through September 2027 and major improvements in benefits as part of what it calls “audacious” demands.