Workplaces across the country could be emptier than usual today, on what has been dubbed National Sickie Day.
Surveys have revealed that the first Monday in February is the worst day of the year for staff faking illnesses, with 300,000 workers expected to take a duvet day.
Employment Law Advisory Services predicts that absenteeism could cost British companies £27 million today as a combination of cold weather, financial problems and winter blues keep employees at home.
Spokesman Peter Mooney said: "Poor weather, long dark nights and a general dissatisfaction with official holidays all mean that early February is a very popular time for workers to give themselves an extra 'duvet day'.
"Add that to the fact that almost three-quarters of the country's skivers prefer to fake illness on a Monday, and that makes today the worst day of the year for employers."
The comments have angered unions, with the TUC commenting that February is right in the middle of the cold and flu season and that the claims are insulting to those who are ill.