The morning after the night before is the main reason in Britain for employees calling in sick, a study published Wednesday showed.

One in five workers opting to stay in bed do so because of over-indulgence, according to 500 individuals surveyed by Unum insurance company. Scots are the most likely to take sick leave in this way.

"These figures reinforce well-documented and worrying trends that people's drinking habits are impacting on their workplace," said Unum's chief medical officer, Professor Michael O'Donnell.

"In 2005/06, there were 187,640 NHS hospital admissions among adults aged 16 and over with diagnosis specifically related to alcohol. This has more than doubled in the last ten years."

After a hangover, the next most frequent pretext for taking time off work on medical grounds is the desire to spend time at home making up after a domestic dispute.