'Germs are loiterers. They can live and thrive on all kinds of surfaces, including - and especially - desks in the workplace.'

London - Britain should switch to a four-day working week to combat stress, a leading doctor has said.

Professor John Ashton, president of the UK Faculty of Public Health, said shorter hours would allow workers to spend more time with their families, get more exercise and reduce unemployment.

Reducing the standard working week from five days to four would also help combat medical conditions such as high blood pressure and mental health problems.

Professor Ashton spoke out after the law was changed to give all employees the right to ask for flexible hours. He said: “When you look at the way we lead our lives, the stress that people are under, the pressure on time and sickness absence, (work-related) mental health is clearly a major issue.”

Britons are notorious for putting in some of the longest hours in Europe, with the average worker clocking up some 250 hours more a year than their German counterparts.

Professor Ashton added: “We’ve got a maldistribution of work. The lunch hour has gone; people just have a sandwich at their desk and carry on working.

“The practicalities of implementing (a four-day week) would be complex, not least because of the high cost of living that prohibits many from working fewer hours.

“Nevertheless, it is important we have a working pattern that is good for our health.”