The UK is "plainly losing" the war on drugs - and may even be going backwards, justice secretary Kenneth Clarke said today.
But he insisted he was personally opposed to decriminalisation and that the government had "no intention whatever" of relaxing the law.
Clarke delivered his gloomy assessment when asked at the home affairs select committee what his long ministerial experience of dealing with the issue had taught him.
"I have not reached the stage of that blinding insight about exactly how we are going to improve our record, is the honest truth," he told the cross-party panel.
"We have been engaged in a war against drugs for 30 years. We're plainly losing it. We have not achieved very much progress.
"The same problems come round and round.
"But I do not despair - we keep trying every method we can to get on top of what's one of the worst social problems for the country and the biggest single cause of crime."
Pressed on whether decriminalisation could be a solution, he added: "The Government has no intention whatever of changing the criminal law on drugs.
"I have frankly conceded that policy has not been working. We are all disappointed by the fact that far from making progress it could be argued we are going backwards at times.
"But my own purely personal view is that I would be worried about losing the deterrent effect of criminalisation of youngsters who start experimenting.
"The really key thing is to try to work out how to get fewer young people to start experimenting with drugs.
"One thing that does put them off is that they would get into trouble with the police."
He said he did believe one area of improvement was that "friction" between Whitehall departments over whose responsibility it was had been lessened.
It "has not vanished but is very, very much less than it used to be", he said, praising in particular coordination between his department and the Department of Health.