Speaking at the first of three live television debates last night, on the issue of public spending on policing Cameron said: "The Metropolitan Police has 400 uniformed officers in its HR department, when our police officers should be crime fighters, not form fillers."
Met Police HR director Martin Tiplady told HR: "These are trainers of other cops, not form fillers."
He added that he was sure the public would prefer that police officers and inspectors were trained by real-life police officers. "It reassures me," he said.
Among the 398 uniformed police in HR are 208 training new police recruits and specials and 26 training new PCSOs. A further 63 are involved in advanced driving training and 30 work assessing would-be sergeants and inspectors.
While it is important that police train police, the Met is still working to find efficiencies where it can. HR will reduce from 398 people to 370 in 2010/2011, Tiplady added.