A team at relationship counselling service Relate has reported a whopping 40 per cent increase in the number of lazy blokes, admitting that, despite being physically able to have sex, they are not interested.

"Men used to come to us with impotence but Viagra has sorted some of that problem. What we have is a lot of men who say, as women did in the fifties: I can have sex, but I don't want to. It's not rewarding.

"Such complaints are unheard of ten years ago. They tend to be men in their thirties, forties and fifties and married. It is a serious issue.

"It counts as a psychosexual dysfunction, rather than just a relationship problem, because these men haven't simply gone off their partner but off sex altogether," the Daily Mail quoted Peter Bell of Relate as saying.

According to Prof Michael King of the Royal Free and University College Medical School in London, depression might be the problem.

"Men are most likely to suffer depression between the ages of 30 and 50. One of the explanations is that men are less able to talk about their problems than women, or express their emotions," he said.