Unifor says bargaining has begun with General Motors for workers at the automaker's CAMI assembly plant and battery facility in Ingersoll, Ont.

The union says the negotiations will focus on higher pay, job security and better pension plans for its unionized workers.

GM is expected to match the pattern set last year during bargaining at its two other plants in St. Catharines and Oshawa.

The union says there's a gap before CAMI workers can receive the same rate of pay as workers at other GM locations because of the different bargaining cycle.

The CAMI plant is the only large-scale electric vehicle manufacturing facility in Canada, building the Chevrolet BrightDrop EV 600 and EV 400.

Workers at CAMI have delivered an overwhelming strike mandate, with 97 per cent in support of a strike action if an agreement is not reached by Sept. 17.