For the past 30 years the legalisation of cannabis for pleasure has been a strong campaigning issue for Law Lords, judges, right-wing MPs and pop stars. But in recent years it has also been championed as a way to help the sick, particularly for easing pain in multiple sclerosis sufferers.
In issuing her controversial call that cannabis should be legalised, or at least decriminalised, the Labour MP Clare Short is thus only the latest public advocate in a long line.
One of the first prominent campaigns came in the now famous letter to the Times in 1967, appealing for cannabis to be distinguished from hard drugs such as heroin, and for possession of the drug to be treated as a lesser offence.
Among the signatories were Jonathan Aitken, who was later to become Minister of State for Defence Procurement in John Major's Cabinet, and TV presenters Brian Walden and David Dimbleby. Others who signed included The Beatles, David Hockney, Graham Greene and the psychiatrist RD Laing.
The advertisement was attempting to capitalise on a climate of opinion that seemed to be moving towards more liberal drugs laws: earlier that year, William Rees-Mogg, then editor of the Times, had written an editorial in support of Mick Jagger, who had just been arrested in possession of soft drugs. Nowadays, Mr Aitken says that "my views on soft drugs have got hard". But the artists and writers on the 1967 letter have been joined by many of today's establishment figures. Mike Goodman, director of Release, the drugs advice charity, said: "The debate is becoming more sophisticated. Now everyone from libertarians to doctors has given different reasons why the law should be changed."
A Home Office survey from last year shows that one in three supports the decriminalisation of cannabis. In a report, it pointed out that fewer deaths were caused by illegal drugs than by tobacco and alcohol.
Although the official stance of the Association of Chief Police Officers is against any easing of drugs laws, a growing number of officers have raised the issue. In July this year, Scotland Yard's director of intelligence, Commander John Grieve, who has consistently urged the police to think the unthinkable on drug matters, warned that "partnership" with drug users was the best option.
Keith Hellawell, Chief Constable of West Yorkshire, and Raymond Kendall, Secretary General of Interpol, have both said the matter should be debated. Among the judiciary, the only prominent voice has been Lord Woolf, a Law Lord, who has spoken out in favour of a review.
Although many MPs on both the left and the free-market libertarian right are privately in favour of a review, it is tabloid condemnation that often prevents public support.
The party most committed to change is the Liberal Democrats. It debated the issue at its 1994 party conference and voted that a Royal Commission should study the question of decriminalisation, prompting the Sun to dub their leader "Paddy Hashdown".
But it is doctors who have added a new dimension to the debate with the mounting case for its use by those who suffer from Aids, cancer, arthritis and epilepsy patients to make their lives more bearable. A British Medical Association study into legalisation of all drugs is due to be published in 18 months.Reuse content