Sir Digby Jones, director general of the CBI, said new research showed that employees in the public sector took off an average of three days more than those in private firms last year.
Early figures from the business group’s annual survey of absence at work revealed that public sector workers took an average of 9.1 days off in 2004 compared with 6.4 in private companies.
The poll of 500 organisations showed that public sector absence cost the economy £4.1bn last year.
The figure would be cut by £1.2bn if the absence rate was the same as in private firms, said Jones.
The findings also revealed that the public sector accounted for 40% of the number of working days lost.
The CBI said its findings, due to be published in full later this week, cast doubt on public sector efficiency targets.
One of the worst government departments for absence was the Department for Work and Pensions.
Jones said: “These findings will make worrying reading for the newly-elected government. If ministers fail to deal with this problem, poorer frontline services or higher taxes will be the result.”
Long-term absence, lasting 20 days or more, was responsible for 57% of total public sector absence, the CBI figures show.
The TUC said closer analysis of the figures showed that public sector workers are less likely to take short periods off work ill than workers in the private sector.