Those caught with marijuana for a second time will be fined £80 and after three strikes will be arrested when drug returns to class B
Cannabis users face new penalties when the drug is upgraded to class B from January next year, the home secretary said today.
Jacqui Smith said that those caught with cannabis for a second time would be fined £80 and after three strikes would be arrested.
The drug was downgraded to class C in 2004, but fears over the increased use of stronger "skunk" strains among young people prompted a policy review and U-turn.
Smith said she was "extremely concerned" about skunk, and its impact on mental health, especially if young people started to use it at an early age or "binge smoke".
Skunk contains higher levels of THC, the active ingredient in cannabis.
"While cannabis has always been illegal, reclassifying it to a class B drug reinforces our message to everyone that it is harmful and should not be taken," she said.
"Fewer people are taking cannabis, but it is crucial that this trend continues. I am extremely concerned about the use of stronger strains of cannabis, such as skunk, and the harm they can cause to mental health.
Smith announced last May that she would go against the recommendations of the government's scientific experts, the Advisory Council on the Misuse of Drugs, which was asked by the home secretary to take its third look at cannabis classification in recent years.
The council's advice was that cannabis should remain class C.
Under current rules, anyone caught twice with cannabis can still walk away with a warning.
Smith said she had accepted police chiefs' calls for escalating penalties for possession in England and Wales.
Smith said: "This is the next step towards toughening up our enforcement response - to ensure that repeat offenders know that we are serious about tackling the danger that the drug poses to individuals and, in turn, communities.
"We need to act now to protect future generations."
Prosecutions and jail sentences for using and supplying cannabis plummeted after the then-home secretary David Blunkett downgraded cannabis in January 2004.
But police began to report that drugs seizures were much more likely to involve skunk than resin or lower strength marijuana.
Humberside chief constable Tim Hollis, who speaks on drugs for the Association of Chief Police Officers, promised a "harder line" on drug users.
"Where cannabis use is repeated or where there are aggravating circumstances locally, officers will take a harder line on enforcement and escalate their response accordingly.
"Every encounter at street level provides intelligence and helps us to act against the criminal gangs who seek to profit from cannabis production and distribution."
Danny Kushlick from the Transform Drug Policy Foundation condemned the move, accusing ministers of "populist posturing".
He said: "Escalating penalties for possession only serve to further marginalise and criminalise millions of otherwise law-abiding people.
"Criminalisation of cannabis possession is discriminatory and disproportionate when compared with tobacco and alcohol possession and counterproductive in so far as it gifts the market to organised criminals and drives the trade underground."
The process for changing the classification of the drug requires votes in both Houses of Parliament. If both votes pass, the new rules will come into force on January 26.
# Hélène Mulholland and agencies
# Monday October 13 2008 16.01 BST