Britain has the highest level of problem drug use and the second highest level of drug related deaths in Europe, according to a report by the independent UK Drug Policy Commission.

There has also been a 68 percent increase in the number of recorded drug offences in the last ten years according to the Home Office.

Shadow home secretary Dominic Grieve attacked the government, saying: "No amount of Home Office spin on this year's figures can hide the fact that class A drug use and drug crime have risen under this government."

"The reason is simple - mixed messages on drugs and a failure to take real action."

Since 2003, the amount of cocaine seized has dropped by 53 per cent, and the amount of heroin seized has dropped 46 per cent since 2001.

The price of cocaine per gram fell from £71 to £45 in 2007 and the cost of heroin per gram from £74 to around £45.

The cost of drug-related crime in England and Wales is estimated at £13 billion.