Boris puts boot into soft judges

The Mayor, who is chairman of the Metropolitan Police Authority, criticised judges in particular for failing to hand tougher sentences to people caught with knives.

In a speech to the London Crimestoppers annual dinner last night he said: "I am worried that the criminal justice system is not fit for purpose and is too often letting us down. I am worried that, where someone is convicted of a knife crime, on too few occasions do we get the sentence we need."

Mr Johnson also said the police initiative Operation Blunt Two, begun last year to reduce the number of teenage killings, had taken more than 4,000 knives off the streets. He said the operation involving the deployment of portable knife arches and stop and searches also resulted in more than 1,000 arrests.

But the Mayor said while police were making arrests, the courts were failing to take tough action against those caught carrying knives. His comments came after it emerged that the knife killer of Harry Potter actor Rob Knox had been sentenced to four years for GBH but was freed early on parole. Karl Bishop served 18 months before his release and his licence period ended weeks before he killed the actor in Sidcup in May last year.

Mr Knox, 18, was one of 28 teenagers killed in London last year, including 22 who were stabbed to death. Conservative leader David Cameron has pledged that his party will adopt a policy under which any offender caught on the streets carrying a knife would face jail. Everyone carrying a blade without a reasonable excuse would be prosecuted and those convicted would be expected to get a custodial sentence.

The Sentencing Guidelines Council issued rules to magistrates last year saying they should fine for first convictions for carrying a blade in public — even though the maximum punishment is four years in jail.

Detectives say gangs and teenagers are increasingly using knives to settle scores.

Statistics reveal that fewer than one in five people convicted of carrying a knife are sent to prison. The most recent figures show that not one knife offender sentenced for carrying a blade in 2007 received the maximum jail term.

Only 17 per cent of people convicted of possession of knives were sent to prison and, of those who were, the majority received sentences of three months or less. The 2007 statistics showed that 6,121 people were convicted of carrying a blade — 160 fewer than the previous year — but only 1,060 of them were jailed, fewer than one in five.