Figures obtained by 5 live Investigates show that the number of ambulance call-outs to prisons in England has increased by nearly 40 per cent in the last three years - with an ambulance being called on average every 45 minutes. 2016 saw the worst disorder in British prisons for two decades. Critics blame overcrowding and staff cuts for an increase in violence between inmates, drug overdoses and suicide attempts. That's leading to more 999 calls - and increased demand for ambulances to ferry sick and injured offenders - and prison officers - to hospital. Justice Secretary Liz Truss has promised to spend £1.4 billion on new prisons and says she'll provide an extra 2,000 prison officers.