Unifor National President Lana Payne announced in Toronto on Tuesday that Unifor and General Motors have reached a tentative agreement, just hours after 4,300 unionized auto workers hit the picket lines at Oshawa Assembly Plant, St. Catharines Powertrain Plant and Woodstock Parts Distribution Centre. “We had no choice as a union but to show General Motors how serious we were about meeting this tentative pattern agreement,” Payne said.