Mephedrone should be handed out in nightclubs, the Government's former drugs tsar said today.
Professor David Nutt said doling out small amounts of the drug with guidance on its use would be "safer" than banning it.
In an interview with the London Evening Standard, Professor Nutt said criminal gangs would be "rubbing their hands" at the prospect of the drug being outlawed by the Government.
Ministers are expected to receive a report from the Advisory Council on the Misuse of Drugs (ACMD) on Monday.
Les Iversen, Prof Nutt's successor, has hinted they will recommend the drug will be made Class B, along with amphetamines and cannabis.
Prof Nutt, who was sacked as ACMD chairman after saying ecstasy was less harmful than alcohol, proposed regulating mephedrone - known as M-Cat or Miaow Miaow - rather than forcing dealers on to the black market.
He told the newspaper: "I wouldn't be against exploring the possibility of some sort of regulated use for MDMA or mephedrone where people, maybe in clubs, could have access to small amounts, safe amounts under guidance."
He added: "It would probably be safer than what we're doing at present."
In a statement released later, Prof Nutt, who now chairs a rival drugs advisory committee, the Independent Scientific Committee on Drugs, criticised the reaction to his comments.
He said: "I have researched in the field of drugs and drug taking for more than 30 years. My approach to the problem is as a scientist.
"My concern is that the undoubted harms of drug taking are minimised and that drug users, of whom there are millions, are protected.
"The reaction to my suggestion that some form of regulated supply of mephedrone, ecstasy and cannabis is worth considering shows just how difficult it currently is to have a balanced, rational and science-based debate around drugs.
"It also shows just how important it is that the Independent Scientific Committee on Drugs continues its work.
"We are committed to ensuring that the British public are able to access high quality, scientific information on drugs and their relative harms."
Teachers' groups called for a ban last week after the deaths of Louis Wainwright, 18, and Nicholas Smith, 19, in Scunthorpe.
Today the family of a 24-year-old woman who died after taking mephedrone paid tribute to their "perfect daughter".
Lois Waters was found dead at a friend's house in the village of Norton, near Malton, North Yorkshire, on Monday.