Jaguar Land Rover is to shed 850 agency staff by Christmas.
Contract workers, working mainly in engineering and IT will go across the group's West Midland sites.
According to the Coventry Telegraph 500 people will be affected at the Whitley site in Coventry, and the Land Rover Gaydon HQ, South Warwickshire.
Sites at Solihull and Castle Bromwich will also bear the brunt of the lay offs.
The move means the company's normal number of 1,700 agency staff will be cut in half, reports BirminghamMail.net.
Night shifts have already been cut at JLR's Solihull factory, which will close for nearly three weeks over Christmas and New Year to avoid stockpiling vehicles.
In September the Tata owned company axed 55 agency worker jobs.
Earlier this month it shed about 600 posts as the recession hit the automotive industry.