Union workers at Volvo Group-owned Mack Trucks overwhelmingly rejected a proposed five-year contract deal and will go on strike at 7 a.m. Monday (2300 GMT), the United Auto Workers said late on Sunday.

About 73% of workers voted against the deal covering 4,000 workers, the UAW said. The proposed deal had included a 19% pay hike.

(Reporting by David Shepardson; Editing by Jacqueline Wong)