The number of sick days taken by staff at British firms has risen for the first time in five years, according to a new report.
The cost of workplace absence is said to be "worryingly high"
Workers took 176m sick days last year costing £11.6bn - up 10m days on 2002.
But employers suspect a large slice of that, 15% or some 25m days, were as a result of feigned sickness.
The poll of 500 firms, by the CBI and insurance giant AXA, came after supermarkets announced a crackdown on sickness leave.
Tesco, Asda and Sainsbury's have decided not to pay staff for the first few days of sickness absence.
The average worker took 7.2 days off last year - an increase of half a day on the previous year, the study suggested.
Average sick days by region
North West - 10.1 days
North England - 8.1 days
Northern Ireland - 8 days
Yorkshire and Humberside - 6.3 days
London - 6 days
Scotland - 5.6 days
And public sector workers took an average of two more days off sick than their private sector counterparts.
CBI deputy director general John Cridland said that while most absence was due to genuine minor sickness, the cost of workplace absence was "worryingly high".
"As costs rose in 2003, many services firms were forced to slim down and
conduct the same amount of work with fewer staff.
"This would have increased pressure on employees and possibly affected
morale, leading to an increase in absence.
"Unwarranted long weekends and staff 'pulling sickies' are taking their toll
on the UK's ability to absorb the enormous cost of absence," he added.
He also said that managers were particularly concerned about staff feigning sickness during this summer's Euro 2004 football tournament.
But TUC general secretary Brendan Barber said the increase in sick days showed that employers, especially in the service sector, were making their staff ill through overwork, bad management and outdated working methods.
"The TUC and CBI need to work together to get employers to concentrate on keeping staff healthy and in work which should be even more important in a struggling sector.
"Over three-quarters of sickness absence is made up of people on long-term sick because employers fail to prevent and deal with serious illnesses such as stress, back pain and occupational asthma," he said.