On behalf of 20,000 civilian specialists in MOD, the union said it supported the stated objective "to give our armed forces the battle-winning kit they need," but was concerned that the potential impact on MOD itself had been neglected.

Prospect National Secretary Steve Jary said: "The strategy is all about retaining industrial capacity with UK industry as a whole and not within the MOD. We have been told by Lord Drayson that the focus is not about the further privatisation of MOD civil servants, but we believe that will be the inevitable consequence.

"Industry will require work to be packaged differently and it will demand to take over ever more in-house functions, such as maintenance, repair and training. This is a threat to MOD capacity and will result in the loss of the skills and experience vital to enable the MOD to act as an intelligent customer, leaving it at risk of being held to ransom by monopoly suppliers."

Prospect points to the privatisation of Royal Ordnance as a key example of its fears. The recent announcement of the closure of the Royal Ordnance factory at Bridgewater, owned BAe Systems will leave the UK totally reliant on a foreign supplier for the explosives used by the UK’s nuclear deterrent.

Said Jary: "We welcomed previous ministerial commitments that in-house options will always be given a chance to compete but we need that position reaffirmed."