Responding to the Liberal Democrats' analysis of figures showing 1.5 million patients in England waited 12 hours or more after arriving at A&E over the past year, NHS Providers chief executive Sir Julian Hartley said:

"These unacceptably long waits for people in pain or distress are symptomatic of an overstretched healthcare service.

"No trust leader wants any patient to have to wait longer than needed, especially as their condition could deteriorate.

"High rates of hospital bed occupancy, delays in discharging patients from hospital and severe staff shortages are all slowing the flow of patients through the system.

"Trusts are working incredibly hard to deliver the national recovery plan for urgent and emergency care, but the task is fraught with obstacles, impeding progress at almost every turn.

"We need sustained investment in services and a longer-term strategy to address the cycle of winter pressures that return year after year.

"A whole-government approach to public health issues, such as obesity and smoking, would also go a long way to help prevent ill health."