A survey by insurers AXA and the CBI shows that public sector staff take an average of nine days off sick each year, compared to 5.8 days in the private sector.
The survey shows absence levels in local government are higher than average, at 9.2 days per year.
The highest absence rates in the public sector were recorded in health and social care at 12.6 days a year. The housing sector totals just five days per year.
Last year the private sector improved its absence levels while the public sector stood still.
The survey found that£1.4bn of taxpayers’ money could be saved if public sector organisations matched the private sector average.
CBI director of HR Policy Susan Anderson said: “We really have to question if there is a medical explanation for the higher levels of long-term absence in the public sector.
“Low morale, poor management and a culture of absence are at least partly to blame,” she added.
The survey also found that while 68% of private employers believe that morale is good or satisfactory in their organisation, only 54% of public sector employers agreed.
More than two-thirds of employers want the government to prioritise the introduction of capability-focused medical certificates or ‘fit-notes’.