Ford is offering 850 of its workers voluntary redundancy packages.
Between 400-500 of the posts are due to go at its Southampton plant by May, where the Transit is built, reports the BBC website.
The decision is due to cost cutting plans.
A recent pay deal will also be renegotiated by bosses at the site who have postponed a decision on the future of Transit production at the plant.
However union representatives said they still expected the pay increase to be honoured.
Local Lib Dem MP Sandra Gidley said she is seeking a meeting with Business Secretary Peter Mandelson over the Ford situation.
The announcement comes as new car registrations fell by 30% in January, according to the Society of Motor Manufacturers and Traders.