Police officers are arresting half as many knife wielding criminals in Croydon as five years ago, official figures reveal.

Of those thugs who are arrested, 40 per cent are being let off with a caution; almost twice the figure cautioned in 2003-2004.

This comes as Metropolitan Police Commissioner Sir Ian Blair accused the courts of being soft on knife crime after revealing only one out of 24 defendants accused of carrying a blade had been sent to jail.

Politicians described the police arrest statistics as “concerning” and questioned whether high profile police initiatives designed to tackle knife crime were working.

Tony Newman, Labour leader on Croydon Council said: “There has to be serious questions over whether the current approach is working.

“If arrests are going down we need to monitor the situation closely.”

Shasha Khan of the Green Party said: “I am concerned we are not targeting the criminals.

“Could stop-and-search be focussing on incorrect profiles? It needs to be intelligence-led or we are likely to create a generation of innocent people being stopped and searched for no reason with the hardcore criminals not being caught.”

Despite police drives such as Operation Blunt to stem the knife crime epidemic in London, the figures show police made just 64 arrests for possession of a knife from April 2007 to April 2008 in Croydon.

The statistics, obtained in a Freedom of Information Act request revealed officers made 126 arrests for the same offence in 2003-2004.

Of the 64 people arrested in 2007-08, 38 were charged and 26 were cautioned, a total of 40 per cent.

In 2003-04, 126 arrests led to 90 charges and 30 cautions - a total of 23 per cent.

The number of arrests for knife crime have fallen each year since 2003. The figures show with an increase of 10 arrests from 2006-07.

Croydon Council cabinet member for safety and cohesion, Steve O’Connell said: “We have to get to a position where people who leave home carrying a knife should expect to receive a custodial sentence when caught.

“I expect operations such as Blunt Two to run as long as there is a problem with knives.

“I want to see people who are caught to be punished severely, an increase in arrests and the judicial system lobbied to increase the punishment for those caught carrying a weapon.”

Borough Commander Mark Gore said: “Croydon police are committed to tackling the serious problem of people carrying knives and other weapons on the streets of the capital.

“This can be evidenced by the tireless range of overt and covert activities being carried out under Operation Blunt Two.

“To address community concerns, Croydon police, together with the whole of the Met police service have adopted a positive charge policy for people caught carrying any weapon in the borough.

“Since the beginning of this financial year over 95 per cent of people caught carrying a knife have been charged.

“This robust stance will continue."