Business leader Sir Digby Jones has urged the new Government to "get to grips" with the level of absence among public sector workers which he said was undermining services.
Sir Digby, 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.
But he was immediately condemned by the TUC which accused him of scaremongering.
Early figures from the CBI'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 £4.1 billion last year. The figure would be cut by £1.2 billion if the absence rate was the same as in private firms, said the CBI.
Sir Digby said: "If Ministers fail to deal with this problem, poorer frontline services or higher taxes will be the result.
TUC general secretary Brendan Barber said: "The CBI wants us to think public sector workers are too ready throw a sickie and take a few days off whenever they feel like it.
"But more serious analysis absence statistics shows the opposite. Public sector workers are less likely to take short periods off work ill than colleagues in the private sector."