Medical experts today urged the Governmen to reclassify cannabis in what would be the first relaxation of the British drugs laws for 30 years.
In a Home Office–commissioned report, the Advisory Council on the Misuse of Drugs (ACMD) recommended that cannabis be reclassified from a class B narcotic to a class C.
They said that although cannabis was still harmful, the current classification was "disproportionate" to its risks to health and to other drugs in the same category, such as amphetamines.
The Home Office said a decision about whether to adopt the proposals would be made after consideration of a pilot project in Lambeth, south London, and a Home Affairs select committee inquiry into the drugs strategy. Both are expected to report within weeks.
The charity DrugScope welcomed the ACMD report as a step towards a more "logical and pragmatic" drugs policy.
But Paul Betts, the father of ecstasy victim Leah Betts and now a drugs awareness campaigner, said it was the start of the "slippery slope" towards decriminalisation.
The report found that the use of cannabis, which has increased dramatically over the last 20 years, was not associated with major health problems and occasional use only rarely leads to significant problems in healthy people.
Experts said the drug's harmful effects were "very substantially less" than those associated with similar use of other class B drugs.
However, even occasional use can pose significant dangers for people with heart or circulation problems and for those with mental health disorders such as schizophrenia.
But both groups are at much more significant risk from amphetamines, the report stated.
The panel said it was not possible to say whether cannabis use led to dependence or a progression to harder drugs.
But they said that despite posing fewer risks than alcohol or tobacco use, it was less harmful than other class B substances.
The report stated: "The continuing juxtaposition of cannabis, with these more harmful Class B drugs, erroneously (and dangerously) suggests that their harmful effects are equivalent.
"The Council therefore recommends the reclassification of all cannabis preparations, to Class C, under the 1971 Misuse of Drugs Act."
Roger Howard, chief executive of DrugScope, said: "It is refreshing to have a Home Secretary who is at last willing to open up the debate on drugs and consider moving towards a more logical and pragmatic drugs policy.
"Today the ACMD has provided the hard scientific evidence that backs up the move to reclassify cannabis and we hope the Home Secretary will quickly implement its advice."
Mr Howard said he hoped the move would end the prosecution of people found with small amounts of cannabis and rejected claims that it would lead to an increase in drugs use.
But Paul Betts said the Government had reneged on its promises to be hard on drugs.
"This has just proved they are liars," he told PA News. "This is the start of the slippery slope. They are scared to say it's dangerous."
Mr Betts accused the Government of softening their stance on the issue because of financial concerns.
"Read between the lines. Why are they doing this? The only thing they're interested in is money. This is a tactical, money–saving exercise.
"Eighty per cent of all crime is drug–related. If you take out half that equation, then you're not going to have people arrested, wasting police officers' time or going to court.
"When it comes to releasing the crime figures in a few months' time, this is clearly to make the Government and the police look good."
The Home Secretary, David Blunkett, commissioned the ACMD to carry out the study in October last year.
The ACMD monitors the state of drugs use and misuse in the United Kingdom and was set up under the 1971 Misuse of Drugs Act.
The Prime Minister Tony Blair's official spokesman said the Home Secretary had made clear he was "minded" to re–classify cannabis, but no decision had yet been taken.
"There are no plans for de–criminalisation or legalisation," the spokesman stressed.
Tory leader Iain Duncan Smith attacked plans to downgrade or decriminalise cannabis as an ill–thought out way to tackle a complex issue.
Speaking during a visit to Langdon College, a specialist residential college in Salford, Mr Duncan Smith said: "Anybody who knows about the difficulties in communities, about young people who are trying drugs and moving on to harder drugs, knows it is far more complex than that."Reuse content