Manpower shortage is 'threatening the armed forces fighting capability'

Family lives are also under threat as servicemen are not given enough time off between deployments, according to a damning report.

Sections of the forces, such as medical staff, are so undermanned there is not enough capacity to give people time off.

At risk: British troops in Afghanistan are being let down by a lack of manpower

The Government has faced criticism over claims the forces are overstretched by the conflicts in Afghanistan and Iraq.

The report from the all-party Commons select committee, released last night, said the forces were reaching crisis point as the number of personnel joining the front line is failing and the number leaving early is increasing.

Staffing shortages mean that personnel are having to spend increasingly long periods away from their families, and gaps between deployments are narrowing.

This is breaking 'Harmony Guidelines', designed to help servicemen rest and recuperate, putting families under 'intense pressure'.

The report said: 'The impact of armed service life on personal and family lives is one of the main reasons that personnel leave.'

Committee chairman James Arbuthnot said: 'Our armed forces are being worked extremely hard to support current operations and it is vital the pressures on our service personnel and their families is minimised.

'However, recruitment and retention targets are being consistently missed, resulting in increased pressure on those who remain. The MoD must respond with sufficient flexibility and imagination if it is to recruit the number of new personnel required to enable our forces to operate effectively.'

Operational capability is particularly threatened by shortages in what are known as the 'pinch point trades'  - specialities where there is insufficient trained staff to properly perform operational tasks.

Trades significantly undermanned include submariners, medical staff, aircrew, mechanics and engineers. In some areas, the manning shortfall is as high as 70 per cent.