Ambulance chiefs are to be hauled before Kingston’s NHS bosses to explain why they are failing to respond quickly enough to 999 calls.

London Ambulance Trust targets to answer within 19 minutes to category B calls - serious but not immediately life-threatening.

Its performance has been red flagged after it slipped to only answering 86.3 per cent of calls in time, missing its 95 per cent target.

PCT chief executive David Smith said: “There is no excuse as far as I am concerned. If targets aren’t being delivered I think it is beholden on us to know why it is isn’t being delivered and what are the recovery plans.”

Board member Julia Gosden said: “This is significantly down against expected target and I know that London Ambulance Service has been invited to the September board meeting to outline to the PCT how they are working to improve.”

An ambulance spokesman said the service in Kingston had actually improved: “The target of meeting 95 per cent of category B calls represents a significant challenge across London, which we are working hard to achieve.

“As part of this ongoing effort to further improve our responses to patients, we are currently in the process of recruiting up to 400 new frontline staff.”