Drugs chief under fire for saying cannabis is safer than alcohol

The Government's chief drugs adviser was expected to be facing calls to resign today after criticising ministers for not reclassifying ecstasy, LSD and cannabis as less dangerous than alcohol and cigarettes.

Professor David Nutt, who heads the Advisory Council on the Misuse of Drugs, accused former home secretary Jacqui Smith of "devaluing" and "distorting" scientific research after she changed cannabis back to Class B.

The academic has called for drugs to be ranked by a "harm" index, with alcohol coming fifth behind cocaine, heroin, barbiturates, and methadone while tobacco should rank ninth, ahead of cannabis, LSD and ecstasy.

In a briefing paper for a lecture at King's College, London, Professor Nutt attacks what he called the "artificial" separation of alcohol and tobacco from other illegal drugs. He also repeats the claim that the risks of taking ecstasy are no worse than riding a horse.

Professor Nutt has been criticised by drugs charities. James Langton, a drugs counsellor with support network Clearhead, said: "If we reclassify cannabis as less harmful than alcohol it could influence more children to take it up."

In the paper, Professor Nutt says the drug classification policy has become "quite complex and highly politicised" and Ms Smith's decision to reclassify cannabis sent mixed messages. He added: "I think we have to accept young people like to experiment - with drugs and other potentially harmful activities - and what we should be doing is to protect them from harm at this stage of their lives. We have to provide more accurate and credible information."

He adds: "If you think that scaring kids will stop them using, you are probably wrong."

The Home Office said his opinions "do not reflect the views of government".