Bill Clinton, 1992

"When I was in England, I experimented with marijuana a time or two, and didn't like it. I didn't inhale and never tried it again."

Jeffrey Archer, 1992

"I don't agree with smoking, let alone cannabis. I've never tried it – certainly not. But you don't have to shoot someone to know about murder."

Sid Vicious, 1976

"Pot is for dropouts. Only hippies like pot."

Gary Barlow, 2007

"In 2002, when I was dropped as a solo artist, I was smoking 15 spliffs a day. At the end of the night, I would smoke only half my last joint so when I woke up I could have the other half before reality set in."

Paul McCartney, 1997

"We [The Beatles] were kind of proud to have been introduced to pot by Dylan – that was rather a coup. It was like being introduced to meditation and given your mantra by Maharishi. There was a certain status to it."

Keith Richards, 2007

"I've quit weak drugs."

Boris Johnson, 2008

"That's true [that he smoked cannabis before university], but the stuff you and I may have smoked is not the same as what the kids are having now. I think skunk is very dangerous."

Howard Marks, 2007

"If, as a result of smoking a lot of dope, one becomes schizophrenic, that's reason for concern. If being slightly schizophrenic makes you want to smoke some dope to ease you through the day, I don't think that's a cause for concern. To find out which of these is true will require research. One has to look into the action [of cannabis] on the brain and what happens."