Nearly 500 shopfloor jobs at Land Rover's Midland factory are to go - as short term contracts and agency staff are told they are no longer required.
Workers at the Lode Lane site in Solihull were informed by letter at the weekend.
Many had expected some jobs to be cut, but the overall figure of 450 far exceeded expectations.
One worker said: "Rumours last week suggested that about 50 people would go.
"The shocking thing is how many people will be going. There are a lot of upset people here because it will be Christmas soon.
"There was no hint it was coming."
The worker said those leaving, including some who had worked at the company since July last year, would go on December 16.
The factory has been working to full capacity this year following the strong sales performance by new models.
Steve Gallant, TGWU plant convenor, said: "As a result of efficiency savings in other parts of the plant, people are moving across to fill spaces agency workers have temporarily been covering."
