With the office Christmas party season in full swing, British businesses could be losing nearly £65 million, according to new figures from Norwich Union.

The research suggests that nearly one million workers have taken sick leave due to over indulgence at the office Christmas party. This adds up to nearly £65 million lost from the British economy because of office party hangovers, based on CBI calculations of absence costs.

But despite the government’s call for people to live healthier lifestyles, the Christmas party spirit has not been dampened, as four in five workers said they will be indulging as much, or more than previous years.

And when it comes to good behaviour women may be watching their alcohol consumption and only plan to drink around half as many units as men, but they are more likely to phone in sick with a made up excuse. But over 50 per cent of men questioned said they would tell their boss the truth.

Illness is a common excuse used by party goers who over do it, with six in ten using the excuse of food poisoning, cold or migraine and another ten per cent claiming to have to nurse a sick relative. Other popular excuses include transport problems and waiting at home for the gas man or plumber.

Other findings from the ‘Hangover Bill’ research include:

Dr Doug Wright, clinical development manager at Norwich Union Healthcare, said: "For most of us staying in bed probably seems the best way to cope with a hangover. Sadly this may not be an option, so keeping up energy levels with regular food and fluids is the best way to get through the working day.

"Obviously the best way to avoid the dreaded hangover is to not drink too much at the party, but if you can’t indulge a little at Christmas when can you! Instead my best advice to avoid feeling rough the next day is to try to drink sensibly by limiting the number of alcoholic drinks you knock back and alternate with soft drinks."