Jack Dromey, spokesman for the five industrial unions at Royal Ordnance, said another 1,000 jobs could be axed by Christmas unless the Government placed a five-year ammunition order.
Workers from 11 Royal Ordnance factories employing 7,000 people in total are to lobby Parliament on Monday at the start of a two-day defence debate.
BAe is to shed a total of 630 jobs in the loss-making Jetstream division at Prestwick, Ayrshire, over the next six months because of the worldwide slump in demand for turboprop aircraft. Compulsory redundancies among the 2,500-strong workforce are expected.
This is the second rationalisation of the business in 12 months. Last September BAe switched production of the Advanced Turboprop from Cheshire to the Scottish site as part of a series of cost-saving measures within its commercial aircraft arm that resulted in 3,000 job losses.
Since then, however, the market for the 19-seat Jetstream 31, 29-seat Jetstream 41 and the ATP has continued to decline and BAe has orders for only a total of 21 aircraft.
BAe hopes to secure a tie-up for the division in the next few months with ATR, a Franco-Italian joint venture, and Saab in the running.
The job losses at Royal Ordnance were blamed on declining Ministry of Defence work.
Some 150 jobs will go at Wescott, near Aylesbury, Buckinghamshire, and a further 70 at the Summerfield plant near Kidderminster, Worcestershire, both part of the rocket motors division.
A further 162 jobs are being shed at Royal Ordnance's weapons fuse factory in Blackburn, Lancashire, because of a 50 per cent fall in orders.
Robin Cook, Labour's trade and industry spokesman, said the latest job losses put BAe, Britain's biggest export earner, on the critical list.Reuse content