By Thomas Moore, Science and Health Correspondent
NHS hospitals are so short staffed on public holidays they are paying almost £150 an hour for nurses to work, a Sky News investigation has found.
On May Day Bank Holiday this year a locum agency was paid more than £1,800 to supply a nurse for a 12-hour shift, new figures show.
And one hospital paid £2,500 for a doctor to work that day.
The statistics - obtained through a Freedom of Information request - lay bare how much the NHS is relying on private locum staff on public holidays.
In one hospital, half of the doctors who worked on May 5 were locum medics.
And at another, almost one third of the nursing staff was supplied by a private agency.
Experts say that using locum staff unfamiliar with the hospitals they are working in can put patient care at risk.
With the NHS under increasing financial pressure, a nursing body wants the amount hospitals pay agencies to be reviewed.
One trust paid nearly £1,800 for a mental health nurse shift. Pic: FileDr Peter Carter, Chief Executive of the Royal College of Nursing, said: "These figures are truly shocking.
"Many (of the nurses) will never have been to that ward before and will probably never be there again.
"It says nothing about continuity of care. Even finding your way round the ward, the geography, it makes life really difficult.
"Agency nurses do not provide good value for money … and the employers who use these extraordinary levels should be held to account for it.
"This is public money that is not being well spent. This is something that should be looked at with the utmost urgency."
Eighty of the 150 NHS trusts in England replied to a Sky News request asking how many locum staff they employed and at what rates on May 5 this year.
At the Heart of England NHS Trust in the West Midlands, half the doctors working that day were temporary locum medics, the figures show.
Experts say a large percentage of locum staff can put patient care at riskMore than three in ten nurses at Shrewsbury and Telford Hospitals NHS Trust and at Southend NHS Trust were from agencies.
Meanwhile, University Hospitals of Morecambe Bay (NHS Foundation Trust) paid an agency £2,500 for a locum doctor to work a single shift.
University Hospitals Bristol (NHS Foundation Trust) paid £1,800 for a nurse on a shift of just over 12 hours - equivalent to almost £150 an hour.
Taunton and Somerset NHS Foundation Trust paid almost as much (£1,798) for a middle grade nurse specialising in mental health - almost a month's pay for the average nurse.
Separate figures published in April suggested that the NHS has spent £2bn on agency staff since 2010/11.
A Department of Health spokesperson said: "We now have 6,700 more doctors and 6,200 more nurses directly employed by NHS organisations than in 2010.
"The figures … are not a full picture of staffing in the NHS, but we encourage all trusts to maintain a tight grip on their staff costs and we will hold poor performers to account."