The United Auto Workers Union is ramping up its unprecedented strike against the nation’s three major automakers and hitting one company where it hurts: pickup trucks. On Monday, in a surprise move from the union, UAW president Shawn Fain announced that more than 6,800 employees are walking off work at a pickup truck production plant in Sterling Heights, Michigan—one of the most important plants to Stellantis, which has reportedly been the most stubborn of the three automakers in negotiations.

“Despite having the highest revenue…Stellantis has the worst proposal on the table regarding wage progression, temporary worker pay and conversion to full-time, cost-of-living adjustments, and more,” the UAW said in a press release.