Union leaders have been called to a meeting with the motor giant Ford amid fears that the company's UK van factory is to close.
More information is expected to emerge following the management and union meeting, which is scheduled for later today.
The union officials said it is a “very worrying time” for the hundreds of employees at Ford's Southampton site.
Production at the plant slumped from 66,000 Transits in 2008 to 28,000 in 2012. Over the years the workforce at the site was reduced to 500, all operating on a single shift.
The plant has made more than 2.2 million Transit vans in the past 40 years.
Unite assistant general secretary Tony Burke said: “This is a very worrying time for the UK workforce. Unite is working hard alongside its European colleagues to get clarity about Ford's plans but the union will not be adding to the current speculation.”
Yesterday Ford announced that its factory in Genk, Belgium, would close with the loss of 4,300 jobs. The company said more details of its “transformation” plan for Europe will be given today.
Stephen Odell, chairman and chief executive of Ford of Europe, said: “The proposed restructuring of our European manufacturing operations is a fundamental part of our plan to strengthen Ford's business in Europe and to return to profitable growth.”
Ford employs 11,400 workers around the UK at plants including Dagenham in Essex, Halewood on Merseyside and Bridgend in South Wales.