Bosses are being advised to end Christmas parties at 11pm in order to keep employee motivation high back in the office the next day.
Research by Aviva UK has warned that a fifth of staff have called in sick the day after drinking too much at work Christmas parties.
The study also revealed that these hangover 'sickies' are costing the economy 39 million hours in absence.
Dr Doug Wright, clinical spokesman for Aviva UK Health, said: "It's important staff have a chance to let their hair down and enjoy socialising with friends and colleagues at this time of year.
"For those who need to drive or operate machinery the next day, the dangers of overdoing it are obvious but being in good form is equally important for many jobs."
Public sector workers drink the most at festive parties, and teachers the least, according to the study.
And, it added, one in ten men don't go to bed at all after the event.
Workers who have a Christmas party this year should count themselves lucky, as last month it was revealed that staff at many Scottish companies, including Stanford life, Aegon and Northern Rock, would have to pay for their own festivities after bosses tightened the purse strings.
Posted by Elizabeth Mewes
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