The Department of Social Protection has the highest level of sick leave of all government departments at 13.5 sick days per employee last year, new figures have revealed.
Numbers are rising at four other departments too despite a promise contained in the Croke Park agreement to cut levels by 10%.
Eamon Devoy, General Secretary of the Technical Engineering and Electrical Union (TEEU), said the context of the statistics must be understood.
"The Department's own survey has established that almost 50% of the staff don't take any sick leave at all," Mr Devoy said.
He also said that European research had established that higher rates of sickness are normal during recession, as a consequence of increased stresses and workloads.