According to sources within Magna, news magazine Der Spiegel reported on Saturday that 3,000 jobs will be cut at production sites, with a further 1,100 administrative positions to go.

The German government had pushed hard for General Motors to sell to the consortium, despite American fears that such a deal could deliver valuable technology into the hands of Russian manufacturers, who are part of the consortium.

Yet ministers are now expecting problems on a European level, with other countries with Opel subsidiaries, such as the UK, Belgium and Poland, possibly complaining that the German government had already pumped €4.5 billion into its Opel – more than the permitted level of state support.

There is also the uncomfortable suggestion that a Belgian Opel factory in Antwerp has been earmarked for closure even though it is more profitable than the one in Bochum, which the plans would retain. Such a decision could prompt the European Commission to withhold the necessary permission for the sale.

Not only this, but the government’s representative at the negotiations, Dirk Pfeil, considers the sale to Magna to be a serious mistake, he told Deutschlandfunk radio on Saturday.

Had he, “known that it was going to be a purely political decision, and that business management considerations would be left in the shadows,” he would not have taken part, he said.

“It is unique in my professional life that the party which has been acting as guarantor also decides on the buyer. That is a bit odd and it does not fit into the system.”

Pfeil said he withheld his vote on the ultimate decision, while former head of Continental tyre manufacturer, Manfred Wennemer, who was also sent to the negotiations to represent the government, voted against Magna.

The competing bid, from RHJ International, a subsidiary of US investment firm Ripplewood, would have reduced the risk taken on by the German taxpayer by €1.3 billion, said Pfeil. Opel employees are now being given a sense of security which does not exist, he added.