Dopey George has a joint on TV

The 43-year-old star, who has twice been cautioned for possessing the drug after being found slumped in his car, lit up backstage in Madrid and defended his use of it.

Michael said of his fondness for cannabis, which is still illegal in Britain: "This is the only drug I've ever thought worth taking ...

"This stuff keeps me sane and happy. I could write without it ... if I were sane and happy. I'd say it's a great drug - but obviously it's not very healthy. You can't afford to smoke it if you've got anything to do."

Michael's comments, reproduced in today's Daily Mirror, are bound to upset many parents and anti-cannabis campaigners.

They come as fears grow over the use of superstrong cannabis such as skunk by increasing numbers of young people.

Skunk has been linked by police to a rise in street violence and burglaries in parts of London.

But during the in-depth TV interview, to be screened on the South Bank Show on 31 October, Michael said cannabis was "very good for creative people".

However, he added a note of caution, stating: "It can be a terrible, terrible drug."

"You've got to be in the right position to take it. You've got to have achieved most of your ambitions because it chills you out to such a degree that you could lose your ambitions."

Michael, who last month was cautioned for possession of the drug after he was found slumped at the wheel of his car near his north London home, said he had dabbled with other drugs, but regretted using all of them except cannabis.

He said: " There's not another drug in my life that I'm glad I took, but grass.

"I think my life might be somewhere else if I'd chosen another avenue. Alcohol for instance . Christ if I drank as much as I smoked. My God, I'd be like Keith Richards."

The interview was filmed over the past two months as Michael prepared for his first world tour in 15 years.

At the start of the programmea message is flashed on screen, reading: "George Michael wishes to inform viewers that the has never tested positive for drink or drugs whilst driving."

As well as referring to the most recent incident this is also a reference to an incident in February, when he was cautioned when found asleep at the wheel of his car near Hyde Park.

Two months later he hit three parked cars and in July he was caught having sex on Hampstead Heath.

Of this Michael tells interviewer Melvyn Bragg: "The public think I'm a man on the brink of a breakdown because I fell asleep in my car, I hit a parked car and because I cruise as a gay man." But he insisted that far from losing control of his life he "feels good". "I'm happy with the music I'm making and I ' m still loaded," he added.