The firm is expected to make an announcement on Tuesday regarding the cuts, which are thought to mainly affect its two plants in Lancashire.

John Cameron, deputy chairman of the union Unite, said it was concerned about a "lack of work going forward".

Up to 10,000 people work at the Warton and Samlesbury plants, where aircraft assembly takes place.

The cuts are believed to centre on the lack of orders for the Eurofighter Typhoon on which 5,000 staff work.

'Reviews operations'

Warton and Samlesbury sites are involved in making parts and the final assembly of the Typhoon fighter.

BAE is yet to make a specific announcement, but a spokesman said the business "continually reviews its operations to make sure we are performing as effectively and efficiently as possible".

"If and when there are any changes proposed we are committed to communicating with our employees and their representatives first," he said.

Asked about the reports, Prime Minister Theresa May's official spokesman said it would be wrong to pre-empt any announcement by the firm.

However, he said: "We do have a long track record of working with BAE Systems and with its works and we'll continue to do so."

'Other opportunities'

Fylde Conservative MP Mark Menzies said it was a "deeply unsettling time" for BAE workers.

But he hoped it would end up the same as in November 2015 when hundreds of redundancies were announced" but few people left.

"In reality, very few people left the business as they were deployed on other projects," he said.

He said the firm would look at other opportunities for the workers, such as on BAE's nuclear submarine and shipbuilding programmes.

Mr Menzies said: "Potentially lucrative contracts on the way from Saudi Arabia, Qatar and others could help sustain these jobs."

He said it was "vital" the Typhoon production line slowed down "to prevent it from having to stop and be restarted in the future".