Loan guarantees to GM Europe and Vauxhall could now fall back under review following the change of government in Britain, although the manufacturer remains confident they will be upheld.
The former Labour administration in the guise of business secretary Lord Mandelson approved guarantees totalling EUR300m (US$367m) to secure operations for Vauxhall in the UK and GM Europe.
However, the incoming Conservative/Liberial Democrat coalition has made it clear it intends to undertake drastic financial pruning and said all significant deals previously agreed will now come under further scrutiny.
"All decisions made by every department from 1 January that need Treasury sign off need to go back to the Treasury," a spokeswoman for the UK's department for business innovation and skills told just-auto.
"There are lots of budgets that have gone forward and if they are considered good value for money, they will go ahead."
The EUR300m loan guarantee was agreed under the UK government's Automotive Assistance Programme
Mandelson had previously said of the agreement: "We need Vauxhall to thrive as part of Britain's automotive manufacturing base and following our negotiations with GM Europe I am confident it will do so."
A Vauxhall statement noted the new government would evaluate former spending commitments.
"We are confident manufacturing in the UK is a sector seen as making a valuable contribution to the UK and deserves government support. It should be noted that Opel/Vauxhall did not request a grant or a loan, but a government backed loan guarantee," it said.
Uncertainty surrounding the UK's position comes as German loan guarantees to Opel as part of restructuring plans are also under intense scrutiny.
A meeting at the German economics ministry tomorrow (4 June) is due to discuss the matter with any final decision concerning the potential EUR1.5bn guarantee slated for next week.
UK Treasury officials were not available immediately for comment.