More than 1400 jobs could be cut at Vauxhall's UK factories, according to reports in the German press.
German newspaper the Frankfurter Allgemeine Zeitung claims that new owner Magna will slash 11,000 jobs from its European workforce, with 1400 of the job losses at UK factories in Ellesmere Port and Luton.
The reports says that more than 4000 jobs will go in Germany, but that Opel's workers in Belgium could be the worst hit with the complete closure of the company's factory in Antwerp.
Carl-Peter Forster, head of General Motors European division and of the Opel supervisory board, said: 'We always said that we would have to restructure in order to stay competitive in the long term, given the massive crisis in the car industry.'
Where the jobs will be lost
According to the leaked report in the Frankfurter Allgemeine Zeitung, the job cuts will be:
Germany - 4116
Belgium - 2517
Spain - 2090
UK - 1373
Poland - 437
Austria - 0
Hungary - 0
Italy - 0
UK concerns over German state aid
GM announced the sale of a majority stake in Opel to Magna and its partner, Russian state-owned lender Sberbank, earlier this month.
Magna was the favoured choice of German Chancellor Angela Merkel, because it would limit the amount of job cuts in Germany.
Britain has raised concerns that the sale will disadvantage Vauxhall factories in the UK, because Germany has backed the deal with 4.5 billion in state aid.
Tony Woodley, of the Unite union, said he had 'growing concerns' over the plans of Magna, which is buying parts of General Motors, including the UK sites.
Mr Woodley also repeated a warning he gave at the TUC Congress last week: "At last the truth is out about Magna's intention towards the UK plants at Ellesmere Port and Luton.
'If these plans to slash jobs at both sites and cut the volume of cars produced at Ellesmere Port are pushed through, then make no mistake, Vauxhall will cease to operate in this country in six years' time.'