The Queen Elizabeth II Centre at Westminster, where the Independent on Sunday conference was being held, is a non-smoking building. So perhaps it was appropriate that the keenest cannabis users had brought hash brownies instead.
Nearly 700 people attended yesterday's meeting - described as the first conference to "openly debate" whether cannabis should be legalised. Delegates ranged from soberly suited doctors and nurses to imaginatively attired hippies and the exotically named Free Rob Cannabis, who changed his name by deed poll to make his point.
The vast majority of delegates had the same aim: a change in the law, whether for civil liberties or for therapeutic purposes. And one of the main points repeatedly made was that the law is strongly enforced in some places whereas in other areas police turn a blind eye.
Colin Sampson would probably raise a wry smile at this. Mr Sampson won pounds 5.4m on the National Lottery a year ago but was in a Sheffield court yesterday admitting possession of cannabis worth pounds 600, and a cannabis plant. He was given a conditional discharge for two years and ordered to pay pounds 50 costs
His solicitor, George Tierney, told Sheffield magistrates that the drug was for Mr Sampson's own use and that, had he not been a lottery millionaire, he would probably have escaped with a caution. "It's fairly true to say that if this defendant still lived on the Stradbroke estate with 2.8 children in a council house, working as he always had, he would not be here and the subject of media attention," he said.
Mr Sampson said later that his lottery win and the publicity that followed had been the trigger for his drugs use. "Although I cannot excuse my illegal acts, the main cause of my unhappiness and subsequent recourse to the use of cannabis has been the unsolicited and unwanted media attention that I have attracted," he said.
Speaking at the conference, Mike Goodman, director of Release, the civil rights organisation for drug users, said a million people will be guilty of cannabis related offences by the millennium if present rates continued. "People should have the right to make decisions over their own lives providing they do not harm others," he said.
Mr Goodman was one of nine speakers, including Professor John Strang, director of the National Addiction Centre, Body Shop founder Anita Roddick, and Professor Colin Blakemore, president of the British Association for the Advancement of Science.
Although debating a drug best known for its relaxing qualities, the discussion grew heated, with cries of "Freedom!' and "Skin up!" as strange smells wafted across the audience.
Nigel Evans, Conservative MP and former chairman of the all party Drugs Misuse Group, urged no change in the law. He said that the idea that decriminalisation would have little or no effect on consumption levels was "several steps removed from reality".
"Keeping drugs as a controlled substance keeps the number of young users down. Decriminalisation removes the stigma of criminality and increases usage," he said above heckles.
Rosie Boycott, the editor of the Independent on Sunday, said it was a "historic debate ... the first time the whole issue of cannabis has been quite so openly debated, a stone's throw away from the mother of parliaments."
She said she had received a letter from the Home Secretary, Jack Straw, saying that the Government was against the legalisation of cannabis.Reuse content