Staff sickness costs the NHS more than £650m a year, according to a new survey of health trusts.

The cost of staff taking time off ill has increased by nearly 7 per cent since 2004-05, the survey of English health trusts found.

Ben Wallace, the Tory frontbencher who carried out the survey under the Freedom of Information Act, said: "The Department of Health is not asking the question about absence rates. There is a failure of the Government to tackle productivity issues in the NHS... The Government has employed huge numbers of extra managers. What are they all doing?"

Official estimates, based on surveys of NHS trusts, show 4.5 per cent of staff time in the health service was lost to sickness in 2005, the latest year for which figures are available, down from 4.8 per cent in 2001. But Mr Wallace criticised the Department for Health for failing to maintain up-to-date analysis of absences, warning the costs were "spiralling out of control".

He said only 78 out of 172 health trusts could give full figures on staff absences, and warned that many did not keep proper records. He added: "Over the past decade, the Government has turned a blind eye to the problem... Ministers seem to be operating a don't know, don't ask, policy."

But Professor James Buchan, of Queen Margaret University College, Edinburgh, said: "The NHS has 24/7 shift working and there is a high degree of stress. Also frontline staff are working with sick people, so they are likely to pick up things like flu."

The Department of Health said it was up to individual NHS employers to minimise sick days.