The US auto workers union halted work at a giant Stellantis truck plant on Monday, expanding a five-week strike hitting Detroit automakers. The United Auto Workers action means that 6,800 workers will walk off the job in Sterling Heights, Michigan, where the European auto giant assembles the highly profitable Ram 1500 pickup trucks. On Friday, UAW President Shawn Fain reported progress in talks with Stellantis, but said further concessions were possible and necessary for a deal that would end the stoppage. The union on September 15 ordered a strike of Stellantis and fellow “Big Three” automakers General Motors and Ford with a stoppage of just three plants with about 12,700 UAW members. But as automakers have improved their offers of pay increases and benefits, the union has kept up the pressure by expanding the strike to additional factories. With Monday’s action, the number of UAW workers on strike now stands at more than 40,000, according to a UAW press release.