Health watchdogs have raised concerns about the amount of time ambulance crews in Oxfordshire are kept waiting at casualty departments.

The Commission for Health Improvement said some paramedics have been delayed for up to six hours at A&E.

Such delays mean they are unable to respond to other emergency calls and patients can be left waiting in corridors on ambulance stretchers at Oxford's John Radcliffe hospital.

But chief executive of Oxfordshire Ambulance NHS Trust John Nicholls said he is confident delays will not be a problem in the future.

'Urgent resolution'

He said: "It's not just us and the Oxford Radcliffe but it's across the whole of the NHS in Oxfordshire where we are trying very hard to ensure patients are seen in a proper and timely manner."

Dr Peter Homa, the commission's chief executive, said: "We have highlighted that the situation is not acceptable and needs urgent resolution.

"Everyone knows that standards vary across the NHS.

"Standards will be raised by the commission across the board by highlighting good practice and by not hiding its findings where improvement is needed."

The commission did praise the trust for its patient-centred culture and for the enthusiasm and commitment of staff across the organisation.