The National Health Service in England will have to take more than £1bn out of its costs this year after its overspend last year doubled to £536m.

In the case of a small number of hospitals that have overspent by tens of millions of pounds, that "could be detrimental to patient care", the National Audit Office warned yesterday. It added that some have such large cumulative deficits that there is a question mark over whether they can remain "going concerns".