Cost-cutting at St Johns Ambulance is resulting in ambulances being pulled off the road when staff are on leave or call in sick.
In a bulletin to staff on Friday, management said the service needs to "actively manage recalls" of back up staff in order to manage expenditure.
The Ambulance Association, representing ambulance officers, says efforts to rein in costs are putting people's lives at risk. Association national secretary
Mark Quin spoke to Charlotte Cook.
