BOSSES at Cornwall's out of hours GP service have denied putting patients at risk despite an internal memo suggesting that staff should manipulate calls classed as "999" to maintain key performance targets. The internal memo which was leaked to The Cornishman indicated that staff at Serco had three minutes to resolve calls which are classed as being serious enough to be an emergency. It suggested that staff should "stop the clock" on such calls by changing the computer processing system used by the company. The e-mail from senior managers said that this would allow call handlers to consult with "floorwalkers" who would decide whether the calls should be referred to the ambulance service. When asked to explain the e-mail Serco said that it was "written poorly" and added that staff had been advised in relation to the issue.