David Cameron will today be urged by MPs to start a wide-ranging public debate on drug policy - including the possibility of legalisation.
The Commons Home Affairs Committee said current strategies were not working and it called on the Prime Minister to establish a Royal Commission to look at all the alternatives.
Following a year-long inquiry, the committee concluded that efforts to combat the drug barons had failed while there was not enough focus on helping users to break their habits.
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Labour strongholds tended to remain so - apart from a major loss for the party in Dudley.
Labour suffered a "terrible" defeat in Rhondda but has already won 16 Welsh Assembly seats as it looks to record a fifth term in office.
UKIP have made further gains in the local elections in the Anglia region and the Conservatives have won back control in Peterborough.