Autoworkers from across Ontario are headed to Windsor to join in a rally across from GM headquarters in Detroit.
The protest against the company's decison to close the Oshawa plant coincides with a GM investors meeting.
Unifor is bussing in protesters from several cities including Kitchener, Brampton and London.
It's the latest attempt at saving jobs.
Earlier this week, unionized workers at the Oshawa assembly plant staged two work stoppages to protest the automaker's decision to close the facility.