Ken Clarke has said the government has no intention of changing the law on drugs and that problem will not be solved by decriminalisation.
He said: "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."
More top news
Dozens of protesters gathered outside the practice of a suburban Minneapolis dentist who killed a protected lion in Zimbabwe.
Ramsay Street, the set of long-running Australian soap Neighbours, is to be transformed into a hotel for fans.
The average Brit spends almost ten years of their lives in front of the television, research has suggested.