Canadian transport giant Bombardier is to review its UK train-making operations after failing to win a contract to build carriages for the Thameslink project.
Bombardier currently operates the UK’s only remaining train factory, employing a workforce of 3,000 in Derby.
Last week the firm found out that it had lost out on the bid to German company Siemens for the estimated £1.4bn deal.
Bombardier said a “full review” would take place as soon as possible, but would not comment on the future of the plant or potential job losses.
“We have told our staff that we realise that this is a period of uncertainty and we will try to ensure that the review is conducted as soon as we can,” a spokesman for the company said.
“However, we are not issuing a time scale. It’s important that this review is conducted thoroughly.”
Securing the Thameslink contract was regarded as crucial for the Derby site as most of its current orders will soon be finished.
The Unite union described the news was a “hammer blow” for Derby and for British manufacturing. It said it would put pressure on the firm and the government to keep the factory open.
The £6bn North-South cross-London Thameslink programme will require 1,200 new carriages.
Transport Minister Theresa Villiers said in a statement that the Siemens-led venture represented the best value for money for taxpayers.
In total, Bombardier employs about 5,000 rail staff in the UK.