Mr Stamp said it was not clear why A&E waits had risen because overall attendances had not increased and demand on the London Ambulance Service was stable. But he said the current-delays pointed to a blip, not a crisis, and affected only "selected" areas of London. Other trusts significantly breaching the Government's four-hour wait limit for A&E patients include Barking, Havering and Redbridge, the West Middlesex and Ealing.