PRESSURE on Charles Clarke to change cannabis back to a Class B drug eased significantly yesterday when the Conservatives abandoned their campaign for reclassification.

The Home Secretary was also urged by experts to stick with the new Class C status to avoid further confusion.

Mr Clarke used an interview in The Times to say that he was very worried about new medical evidence linking cannabis consumption to mental health problems, and admitted that the decision to downgrade the drug had confused the public. He will have to announce in a few weeks whether or not to reverse the decision, which was made by David Blunkett, his predecessor, two years ago.

Over the Christmas break, the Home Secretary has considered a report from the Advisory Council on the Misuse of Drugs. Leaks suggest that the report says that cannabis poses a more serious risk to mental health than previously thought, but stops short of recommending reclassification.

David Cameron, the new Tory leader, made it clear yesterday that he would not put Mr Clarke under any pressure to reclassify the drug. At the general election, the Tories said they would reverse Labour’s decision on cannabis and change it back to class B.

David Davis, the Shadow Home Secretary, also called for reclassification during the Conservative leadership campaign, but he issued a statement yesterday welcoming Mr Clarke’s decision to voice concern over the impact of the drug on mental health and looked forward to further debate.

“We welcome the Home Secretary’s recognition that there is new evidence about the dangers of cannabis, particularly with regard to mental health,” Mr Davis said. “We look forward to the publication of the advisory council’s report and appropriate action from the Government, in particular to protect young people.”

Mr Cameron, who has refused to deny that he used drugs as a student, said during the leadership contest that he was undecided whether cannabis should be upgraded.

Martin Barnes, chief executive of the charity DrugScope and a member of the advisory council, implored Mr Clarke yesterday to abide by the expert advice. “There has been some more recent research that does indicate that cannabis may cause mental health problems, whereas in the past it was accepted that it could potentially worsen existing mental health problems,” he said.

“Since cannabis was reclassified there has been much more debate about the harms and actually some indication that the use of cannabis has started to decline. So on that basis I think it would be quite difficult to explain why we have to move it back to B.”

Mr Barnes said that if the advisory council recommended no change, the Government would need very compelling reasons to go against it.

Dame Ruth Runciman, who chaired the Police Foundation report that first recommended the downgrading of cannabis, said that there had been no significant increase in use of the drug since it was downgraded. She said the move had been sensible but had been very badly handled and created much public misunderstanding.

“To rereclassify is as ill-judged as it can be in my view,” she said yesterday. “I think it will add greatly to the confusion. I think it is a very ill-judged thing to do and that it actually puts cannabis where it does not belong in the scale of relative harm.”

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