Cannabis is reclassified as a class B drug with effect from 26 January 2009. Reclassification of cannabis to a Class B drug has a number of consequences in terms of maximum penalties. For possession of cannabis as a Class B drug, the maximum penalty on indictment increases from 2 to 5 years’ imprisonment. On summary conviction, in respect of which the majority of possession cases are dealt with, the maximum imprisonment penalty remains the same at 3 months, although the maximum fine that the Magistrates’ Court can impose increases from £1,000 to £2,500. For the supply and production offences for cannabis, the maximum penalties on summary conviction increase to 6 months’ imprisonment and/or a £5,000 fine (from 3 months and/or a £2,500 fine respectively). The penalties for other offences relating to cannabis are unaffected, including the maximum penalty on indictment for supplying or producing cannabis of 14 years’ imprisonment and/or an unlimited fine.
That should do it, then. The menace of marijuana is as good as defeated.
Here's a piece from The Times, describing the chaos.