"My colleagues who deal with the MoD think that it is bound to include some people who work in IT - but we don't have figures," the spokesperson said.

According to The Guardian, Brennan's letter states: "In the SDSR we planned for...a 25 percent reduction in the cost of civilian personnel by 2015, bringing the size of the MoD civil service down to a total of some 60,000 civilian posts.

"As part of the package announced last week we need to make further reductions in...civilian manpower. For civilians, we will be extending the earlier planned reductions, coming down to a total of 53,000 civilians by 2020".

The MoD expects most of the job cuts to come through "natural wastage" with compulsory redundancy being a "last resort".