David Batty, Deborah Summers, Matthew Tempest and agencies Guardian Unlimited
Five members of the cabinet, including the chancellor and home secretary, today admitted they had smoked cannabis in their youth.
The chancellor, Alistair Darling, was the most senior member of Gordon Brown's new government to confess he had smoked cannabis "occasionally in my youth".
The shock admission, from the secretary of state best known as a "safe pair of hands", came after the home secretary, Jacqui Smith, revealed that she had dabbled with the drug during her
The disclosure - made while Ms Smith discussed the prime minister's announcement yesterday of a review into whether marijuana should be reclassified back to class B after it was downgraded to class C three years ago - prompted an avalanche of similar admissions from her cabinet colleagues.
Ruth Kelly, the transport secretary, John Hutton, the business, enterprise and regulatory reform secretary, and Andy Burnham, the chief secretary to the Treasury, also confirmed today they too had experimented with the drug.
Hazel Blears, the communities secretary, and housing minister Yvette Cooper have both previously admitted to smoking dope in their youth.
Confirming that Mr Darling and Mr Burnham, had both tried the drug, a Treasury spokesman said: "The chief secretary said he had tried it one or two times at university but never since."
Asked this morning by GMTV whether she had tried cannabis, Mrs Smith said: "I have. I did when I was at university. I think it was wrong that I smoked it when I did. I have not done for 25 years."
Home Office ministers Tony McNulty and Vernon Coaker later admitted that they too had smoked marijuana as students.
Mr McNulty told BBC News 24: "At university I encountered it, I smoked it once or twice, and I don't think many people who were at university at the time didn't at least encounter it."
A spokesman for the foreign secretary, David Miliband, said the minister had never tried cannabis. A spokesman for the prime minister also confirmed that Mr Brown had never used the drug.
The home secretary is due to formally announce the review next week as part of a wide-ranging drugs inquiry that in part reflects concern about skunk, a stronger form of cannabis being blamed for an increase in mental health disorders.
If cannabis were returned to class B, anyone in possession of the drug would again be liable for arrest.
It was downgraded in 2004 while David Blunkett was home secretary. Since then, concerns have grown among doctors and MPs that its classification does not reflect the health dangers it poses.