The United Auto Workers union is escalating its fight with some of America's biggest carmakers by taking strike action at dozens of parts distribution centres across the US.
UAW boss Shawn Fain said the new walkouts would hit 38 sites owned by General Motors and Stellantis, as the row over pay and benefits continues.
The move excludes Ford, which the UAW said was making more progress in talks.
The UAW declared a strike against the three carmakers last week.