Britain relaxes law on cannabis
In most cases, possession of the drug will not lead to arrest.
LONDON, England (CNN) -- Laws against cannabis in the UK have been relaxed in the biggest shake-up of Britain's drug laws in 30 years.
The drug has been downgraded from a class B drug to class C -- putting it in the same category as tranquillizers and anabolic steroids.
The government stresses the drug remains illegal.
However, in most cases, possession of the drug will not lead to arrest. An on-the-spot warning will be given, and the drug will be confiscated.
The Association of Chief Police Officers has drawn up guidelines saying arrests should only be made in aggravated circumstances, such as smoking the drug outside schools.
The maximum prison sentence for possession has been lowered to two years from five.
Britain's Home Secretary David Blunkett said he expected the move would lead him to "take a bit of stick over the next few weeks."
The British Medical Association (BMA) says it is "extremely concerned" the move will mislead users into thinking it was safe.
"Chronic cannabis smoking increases the risk of heart disease, lung cancer, bronchitis and emphysema," BMA deputy chairman Dr Peter Maguire told the UK Press Association.
"The public must be made aware of the harmful effects that we know result from smoking this drug."
Ministers say the move is designed to free up police to be able to target hard drugs like cocaine and heroin.
The Government has launched a press and radio advertising campaign to educate people about the change in the law.