The Mayor of London has come under fire for appointing a Labour politician to lead a unit set up to reduce gun and knife crime.

Mayor of London Sadiq Khan today announced he had appointed Lib Peck – the Labour leader of Lambeth Council – to head his violence reduction unit.

The unit, which was set up last year, brings together specialists in health, police and local government to apply the approach of tackling violent crime successfully used in Glasgow, in which it was treated as a public health issue.

The unit aims to cut knife and gun crimes by intervening in potential offenders’ lives at an early age.

But London politicians have hit out at Mr Khan for this appointment, suggesting he has used the opportunity to appoint his friend rather than the best person for the job.

Caroline Pidgeon, the Liberal Democrat London Assembly member, said: “I am surprised and utterly disappointed to see a Labour politician appointed to head the new violence reduction unit at City Hall.

“If we are to turn around the growth in violence across the capital we need professional experts in this field heading this unit and delivering, not career politicians who are the mates of the Mayor.

“Sadly, Sadiq Khan has been too slow to act in adopting a public health approach to tackling violent crime and now he is failing to find the best people to deliver the changes London so desperately needs.”

Susan Hall, Conservative Assembly Member for Harrow, said the decision shows Mr Khan is guilty of “blatant cronyism”.

Ms Hall said: “Rather than appointing someone with the skills and experience required to get to grips with London’s crime epidemic, the Mayor has chosen to appoint an old political ally and Labour leader of Lambeth Council.

“Lib Peck’s track record hardly qualifies her for this role; Lambeth is the fourth worst performing borough for crime, with gun crime rocketing over the past year”.

Conservative Assembly Member for Havering and Redbridge, Keith Prince, said he hoped an ex-police officer would have been given the job and said he was “disappointed” by the Mayor’s choice.

Mr Prince added: “I would have expected someone who has more experience and has a track record working in crime to have been appointed.

“It would have been an opportunity for him to show the job is not all about politics. The people of London will now be asking if this decision is about the job which needs to be done or politics.”

Ms Peck will step down as the leader of Lambeth Council to work as part of the unit, which has already had £6.8 million in investment from City Hall.