The government’s chief drugs adviser has strongly indicated the Advisory Council on the Misuse of Drugs (ACMD) will recommend mephedrone be banned.
Professor Les Iversen said he expected the panel would make a recommendation to the home secretary next Monday.
He said he believed mephedrone was “harmful” and hinted that it should be categorised as a Class B drug.
His evidence to an MPs’ committee comes as the deaths of a number of young people have been linked to the drug.
The drug is known by various names, including “M-Cat”, “MC”, “mieow”, “meow”, “4MMC” or simply plant fertiliser.
Concern over its effects has grown after two friends, Louis Wainwright, 18, and Nicholas Smith, 19, died in Scunthorpe, Lincolnshire, last week after taking mephedrone.
Since then a number of other deaths have been investigated to see if they are connected to the drug, including that of a 24-year-old woman who died in North Yorkshire on Monday.
He said a plan by Liverpool John Moores University to use students as guinea pigs in a research experiment on the drug was “pretty unethical”.
Psychologists at the university have recruited 50 students for a study into the effects of mephedrone.
Websites selling the drug have told their customers it is a case of “when” not “if” mephedrone will be banned.