Charges of unfair labor practices, which the UAW filed Thursday against General Motors and Stellantis, are rare in modern Detroit 3 bargaining and mark an escalation of tensions that could shape how a potential strike plays out.
The union submitted the complaints to the National Labor Relations Board, alleging the two companies are "refusing to bargain in good faith over mandatory subjects of bargaining including but not limited to wages and benefits."
Both GM and Stellantis disputed the charges. The NLRB on Friday said it would investigate.
While such complaints are common, especially against nonunionized automakers, the UAW and Detroit 3 are known to have taken this step against each other only a handful of times.