Union leaders have accused Vauxhall of "dumping on" British workers after the car manufacturer admitted that it wants to cut about 850 jobs at the Ellesmere Port, Cheshire plant.

Sir Ken Jackson, general secretary of the newly formed Amicus union said Vauxhall was singling out British staff because they were easier to remove than their counterparts in mainland Europe.

The subsidiary of General Motors has already announced that it is cutting 2,000 jobs at its Luton plant, where car produc tion will cease at the end of March.

"Ellesmere Port has a committed and highly skilled workforce who deserve better treatment than this. We were promised that the pain of job losses would be shared across Europe, but once again it is British workers who have been dumped on," said Sir Ken.

The Transport & General Workers Union (TGWU) followed up the attack saying the proposed cuts were part of a General Motors cost-cutting programme called Project Olympia. "Vauxhall must come clean over their plans for the UK. First, they said Luton must close to make them more efficient and they transferred the work to Ellesmere Port. Now, before the ink is dry on that move, they are starting the incremental attack on Ellesmere Port," said Bill Morris, TGWU general secretary.

But Vauxhall last night denied that there was any targeting of the UK workforce. "This [the cutbacks] is something we need to do at Ellesmere Port for Ellesmere Port," said a spokesman, who insisted that no compulsory redundancies were expected.

Vauxhall has recently in jected £200m into the Cheshire plant to gear it up for producing a new Vectra alongside the successful Astra model which has traditionally been built there.

The company has not finalised the exact numbers that would be surplus to requirement under a drive to make the plant more competitive and flexible.

"A limited number of early retirement and separation packages will continue to be offered, and no compulsory redundancies are expected. The final details have yet to be concluded. We are also continuing to look at ways to work more closely with our supplier base in the area," said the Vauxhall spokesman.

The remark is understood to refer to company plans to "outsource" half of the 850 surplus jobs to its suppliers in the region.

Ellesmere Port employs 4,300 workers who produced 150,000 Astra models in 2001 but a smaller number of employees are expected to produce 185,000 Astras and Vectras this year.

Vauxhall last year sold 310,000 cars in Britain, with 70,000 coming from Luton and 90,000 imported from its facilities in Belgium and Germany.