Dear Mr Corbyn,

In your speech at the Labour Party manifesto launch you said that “violent crime has doubled under the Conservatives’ austerity programme.” I understand that you were referring to increases in the number of violent offences recorded by police forces.

This is a complicated area, with two main sources of data.

As the crime bulletins from the Office for National Statistics make clear, the best measure of trends in overall violent crime is the Crime Survey for England and Wales, which is not affected by changes in recording practices and police activity. The Crime Survey shows little change in overall violent crime in recent years.

However, while police-recorded crime has significant limitations, it is better suited than the Crime Survey to measuring trends in some of the more harmful crimes that occur in relatively low volumes.

Yours sincerely,

Sir David Norgrove