Members of the Cabinet lined up to tell of their drugs experiences, or lack of them, yesterday after the Home Secretary revealed that she had smoked cannabis at university.

Jacqui Smith’s “confession” in early-morning television interviews triggered similar displays of candour from her colleagues, with the unlikely figures of Alistair Darling, the Chancellor of the Exchequer, Ruth Kelly, the Transport Secretary, and John Hutton, the Business Secretary, all admitting that they had tried drugs.

By last night eight members of the Cabinet – including John Denham, the Universities Secretary – had said they had tried drugs, and two other Home Office ministers, Tony McNulty and Vernon Coaker, had joined the roll call of student drug-takers.

The disclosure by Ms Smith became inevitable when Gordon Brown – who has never taken illegal drugs, according to his spokesman – put her in charge of the review of the 2004 declassification of cannabis from a Class B to Class C drug.

Her Cabinet colleagues were then contacted and by last night about a third had said that they had tried cannabis, a third that they had not, and a third had refused to comment.

The openness of so many Cabinet members appeared designed to put David Cameron on the spot over his refusal to answer questions on drugs. A biography of the Tory leader disclosed that when he was a 15-year-old pupil at Eton he was punished after becoming involved in a drug-taking scandal, but Mr Cameron has refused to comment on the issue. Most Tory spokesmen appeared to be taking a similar line yesterday, saying that they did not take part in surveys. But David Davis, the Shadow Home Secretary, was adamant that he had not taken drugs.

Mr Brown was said to be relaxed about the admissions, and his spokesman said that he regarded how his ministers dealt with the question as a personal matter. Perhaps the biggest surprise was Ms Kelly, who is a practising Roman Catholic. A spokesman for her said that she had smoked the drug in the youth, realised it was foolish and given it up.

Almost as big a shock was Mr Darling, who said: “Occasionally, in my youth.” His deputy, Andy Burnham, the Chief Secretary, said “once or twice at university and never since”.

Mr Hutton smoked cannabis at university more than 30 years ago. His spokesman said: “He now regrets doing it, having seen the damage that cannabis can cause among some of the young people in his constituency.”

Hazel Blears, the Communities Secretary, and Yvette Cooper, the Housing Minister, who has the right to sit in the Cabinet while not being a full member, have in the past admitted trying cannabis.

Ms Smith’s first admission came on GMTV. “I think it was wrong that I smoked it when I did,” she said. “I have not done for 25 years. I share other people’s concerns about the effect that cannabis has on young people and mental health problems.

“So, actually, I think that in some ways I have learnt my lesson and I have a responsibility as Home Secretary now to make sure we put in place the laws and the support and information to make sure we carry on bringing cannabis use down, which we are doing.”

Asked if her admission might make her unfit to be Home Secretary, she said: “On the whole I think people think human beings should do jobs like this. I am not proud about it; I did the wrong thing.”

Mr McNulty said: “Jacqui is a very straight and honest person and gave a straight answer. I think what went on 25 years ago when people were 18, 20, was entirely different from where people are today. Anyone who went to university in the late 70s or early 80s would have encountered and may have consumed cannabis.

“I certainly did, just like Jacqui did, and I think people would be more surprised if you had managed to avoid it.”

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