Detroit, Michigan - United Auto Workers (UAW) President Shawn Fain has filed a complaint against Tim Scott after the Republican senator suggested striking union members should be fired.

GOP presidential hopeful Tim Scott is in hot water after Fain filed an official complaint with the National Labor Relations Board (NLRB) on Thursday.

The UAW leader's action came after the South Carolina Republican spoke out against the union's historic Stand Up strike against the "Big Three" carmakers – General Motors, Ford, and Stellantis – during a Monday campaign rally in Iowa.

"I think Ronald Reagan gave us a great example when federal employees decided they were going to strike," Scott said. "He said, 'You strike, you’re fired.' Simple concept to me, to the extent that we can use that once again."

Ukraine conflict Russia using "significant" number of North Korean troops against Ukraine, Zelensky claims

Fain's complaint accuses Scott of violating federal labor law in his capacity as an employer for his campaign by threatening workers with consequences for engaging in protected union activity.

"Just another example of how the employer class abuses the working class in America, employers willfully violate labor law with little to no repercussions," the UAW president wrote on X. "Time for more stringent laws to protect workers rights!!"

The UAW announced it was expanding its strike to 38 more plants on Friday as the massively profitable automakers continue refusing to meet workers' basic needs in contract negotiations.