He added: “We are hoping to sit down with our colleagues in Europe as soon as possible to find out what is in the bid and the offer.”

Ellesmere Port and Neston Labour MP Andrew Miller, whose constituency includes the plant, vowed to fight for increased production volumes for the site.

He said: “Magna have given an unambiguous commitment to continue manufacturing at Ellesmere Port, which is to be welcomed.

“However, the number of vehicles they are talking about is, in my view, inadequate to ensure we are as competitive as we can be.

“I will be fighting to get the volume up so that we cannot only guarantee the competitiveness of the site but put us in a strong position to continue the work in getting the next generation that is the Ampera electric vehicle, which is well within our grasp.

“It is by no means a finalised contract and the important thing is despite the uncertainty we have got to continue to focus on launching the new vehicle and getting that right and prove that Ellesmere Port was the right choice because of the workforce and their commitment to quality.

“There is no reason why any new owners should not say, ‘we have a world-class plant here and one fifth of GM’s market is in the UK and we need to continue’.”

Tony Woodley, Unite the Union joint General Secretary and a former Vauxhall worker, called on the UK Government to work with Magna to ensure the best possible future for Vauxhall.

“The uncertainty surrounding the ownership of Vauxhall is now over, but the uncertainty surrounding the long term future of Britain's plants will continue.

“With that in mind, the union and the Government will no doubt continue to negotiate with Magna.”

He added: “We expect financial support from the UK Government for Magna.”

Business Minister Pat McFadden said: “

“Now GM has announced its preferred bidder is Magna, we will continue our discussions with Magna.

“They have told us of their commitment to continuing production at both Ellesmere Port and Luton, and we will work to make sure we get the best possible outcome for the UK.”

While Magna was announced as the preferred bidder yesterday, further talks could still continue for another six to eight weeks before contracts are signed.