Sick leave taken by public sector employees is costing at least £4 billion a year, according to a new survey.

Data released by the Chartered Institute of Personnel and Development suggests that if ministers cut the public sector illness rate to that seen in the private sector they would save around £1 billion annually.

The figures are embarrassing for ministers as they seek to implement the Gershon proposals on increasing efficiency in the public sector.

A programme to cut the 12-day average absence rate in the Department for Work and Pensions has so far failed, according to the research.

The Public and Commercial Services Union has said that "bullying" by senior managers is making matters worse.

That claim appeared to gain some support from the figures, which found that stress is a growing cause of absence. It is the biggest cause of long-term absence for non-manual workers and the fourth biggest cause for manual staff.

Sick pay

But Monday's newspapers reported that chancellor Gordon Brown wants to withhold sick pay from civil servants.

Absence levels in the public sector average 10.7 days a year, compared to 7.8 days in the private sector.

The average cost of absence now stands at £588 per employee per year, a rise of 3.7 per cent on last year's figure according to CIPD.

But absence costs in the public sector are higher, at £706 per employee.

"A large part of managing stress is about good people management," said report author Ben Willmott.

"It is about providing employees with well-defined jobs roles, challenging but realistic targets and the support, training and recognition to help them achieve these targets.

"Although it is worrying to see stress-related absence on the increase it is encouraging that employers are taking action to address this."

The survey also finds concerns among experts that the sick-note system, which is under review by the Department for Work and Pensions, does not function effectively.

Human resources professionals are concerned that sick-notes are issued too easily because GPs don't have enough time or the necessary expertise in fitness for work issues.