Car production has ceased at the Fiat Chrysler Automobiles NV assembly plant in Brampton, Ont., amid a strike by workers at the Lear Corp. factory that supplies seats for the vehicles assembled in Brampton.

Workers at Lear in Ajax, Ont., went on strike on the weekend, then on Tuesday overwhelmingly rejected a tentative agreement between the seat maker and Unifor that would have ended the walkout.

Employees on the morning shift at the Fiat Chrysler Brampton plant reported for a partial shift Wednesday morning, but the afternoon shift was cancelled for all production employees except skilled trades workers, a Fiat Chrysler Canada spokeswoman said.

Story continues below advertisement

Seats are shipped to Brampton from Lear’s Ajax plant on what is known in the auto industry as a just-in-time basis, which means they are sent to the assembly line within a few hours of arriving on the loading dock. Seats are not kept in inventory at assembly plants, so a shutdown of a seating supplier quickly causes an assembly plant to halt production.

About 320 people put together the seats in Ajax. Wages are the main issue in the labour dispute, sources familiar with the talks said.

Workers in Brampton assemble the Chrysler 300 and Dodge Charger and Challenger full-sized vehicles – the only passenger cars remaining in the lineups of those two brands.

Those cars have been performing better than many in the passenger car segments in North America.

Sales of 300 fell to 16,905 in the first four months of the year from 19,011 a year earlier in the U.S. market, which is the destination for about 80 per cent of what comes out of the Brampton plant. Charger sales dipped to 27,897 from 29,256, while Challenger deliveries grew to 23,450 from 22,316.

Production of the three cars rose 4 per cent last month to 22,165 from 21,395. In the January-April period, output dipped 2 per cent to 54,564 from 55,725.