Opinions on drugs are sharply divided within Parliament
By admitting smoking cannabis while she was a student, Home Secretary Jacqui Smith is the latest in a series of British politicians to find themselves in the spotlight over their alleged youthful use of soft drugs.
From former Conservative chairman Francis Maude to former home secretary Charles Clarke a procession of high-profile figures have admitted puffing cannabis in the past.
More recently, on becoming the minister for drugs policy, Vernon Coaker admitted having "one or two puffs of marijuana" while a student.
On the other hand, Tory leader David Cameron has never admitted previous drug use.
But the issue of whether he smoked cannabis while a student has dogged him since he joined the Tory leadership race two years ago.
Back then, when questioned by Observer journalist Andrew Rawnsley at a party conference fringe meeting, he said: "I had a normal university experience, if I can put it like that."
In a later television interview, he said: "I did lots of things before I came into politics which I shouldn't have done. We all did."
Later he repeated his current non-committal stance when he told BBC One's Question Time: "I'm allowed to have had a private life before politics in which we make mistakes and we do things that we should not and we are all human and we err and stray".
Commentators at the time said Mr Cameron's reluctance to admit any "indiscretions" were understandable given he was in the midst of a fierce leadership contest.
Mr Rawnsley said at the time that, far from ending speculation, owning up to any recreational drug use would lead to more questions such as "what did he take?" and "how much?".
The danger, Mr Rawnsley said, is that Mr Cameron would appear "evasive" - an image he could not afford to see take hold among voters.
Mr Cameron has faced continuing questions over drugs
Several of Mr Cameron's Conservative colleagues - including his leadership rival Ken Clarke - backed his right to remain silent.
But even with politicians increasingly calling for a "mature debate" on the drugs issue - and previously taboo subjects such as homosexuality increasingly acceptable in Westminster - drugs remains a tricky area.
Drug abuse and its impact on society remain current and often controversial political issues.
When in 2000, then shadow home secretary Ann Widdecombe came up with the idea of £100 fines for people caught with even the smallest amount of cannabis, the policy was instantly undermined by a parade of shadow cabinet ministers owning up to past drug use.
Eight members came out as having used cannabis, including Francis Maude, shadow industry secretary David Willetts and shadow environment secretary Oliver Letwin.
Tim Yeo, then agriculture spokesman but now a backbencher, told the Times: "I was offered it on occasion and enjoyed it. I think it can have a much pleasanter experience than having too much to drink."
His career did not seem to suffer a permanent hangover, as he later became party spokesman on both health and education.
Labour's Charles Clarke admitted in 1997, the year he became an MP, that he had taken drugs "a couple of times in my late teens". He later became home secretary.
In 2002, having left politics, the late Mo Mowlam wrote in her autobiography that she had tried cannabis.
Then drugs czar Keith Halliwell said he advised Ms Mowlam to come clean about her youthful experimentation after learning she was involved with drugs at university.
In 2003 Caroline Flint, as the newly appointed government minister responsible for drugs policy, admitted she took cannabis as a student but did not like it.
Altogether, at least 32 current MPs have gone public over previous drugs use.
But like much else in politics, a lot depends on the timing and context of any admission - and whether there has been attempt at a cover-up.
The highest-profile politicians - the leaders or would-be leaders - still tend to remain coy, or adamant in denial.
Former US President Bill Clinton famously admitted using cannabis, but not inhaling.
Former Prime Minister Tony Blair was criticised in some quarters for inviting unashamed drug user Noel Gallagher to Number 10.
But on the subject of whether he has ever taken illegal drugs himself, Mr Blair remained silent.
Mr Cameron is clearly determined to follow his example and remain tight-lipped on the subject.