Temporary staffing costs at the region's busiest Accident and Emergency department more than quadrupled in the space of a year, it has emerged.

A union has raised its concern about a 'recruitment crisis' in emergency medicine after locum and agency costs at the Norfolk and Norwich University Hospital rocketed from more than £400,000 in 2012 to £1.8m last year.

Fears have also been raised about the cost of over relying on temporary staff in the NHS after it emerged that the N&N paid an agency nurse more than £1,000 to cover a 12 hour shift during the August bank holiday.

Officials from the Colney hospital said that locum costs had increased because of the formation of a new immediate assessment unit at the hospital's A&E to increase capacity and reduce ambulance turnaround delays.

Figures obtained under a Freedom of Information request revealed that the N&N's spending on A&E locum or agency doctors rose from £309,954 in 2012 to £1.3m in 2013. Bank and agency nurse costs also increased from £108,378 in 2012 to £496,884 last year.

The figures come after officials from the Clinical Commissioning Groups (CCG) for Norwich, North Norfolk and South Norfolk pledged to provide an extra £2.5m last April to pay for more than 20 new nurses and doctors within emergency care.

Dr Mark Porter, chairman of the British Medical Association Council, said limited resources and gruelling workloads were putting strain on the NHS.

'In some specialities, such as emergency medicine, this has contributed to a recruitment crisis and means that because existing doctors are working flat out to meet rising demand an increasing number of locums are being used.'

'Whilst locums have always been an integral part of the NHS workforce when there are periods of high demand or staff absences, they should not be used as a long term solution to gaps in the NHS workforce. As these figures suggest, they can be more expensive to employ than permanent staff, resulting in additional costs for an NHS that is already struggling with declining budgets.'

'To stem this problem the government urgently needs to address issues around workload pressures, resourcing and work-life balance. Only by making working practices and environments safe and sustainable will the NHS be able attract and retain the required number and mix of doctors,' he said.

Commissioners pledged extra funding to the N&N last year to put in place measures to reduce long ambulance delays at the front doors of A&E. The hospital hit its target of seeing 95pc of patients within four hours at A&E during the winter months.

A spokesman for the N&N said: 'Over the last few years we have significantly increased our staff establishment in A&E, to reflect the increasing numbers of patients using our services. We have also created an Immediate Assessment Unit (IAU) in A&E to improve the service for patients and have created 40 whole time equivalent posts and two extra consultant doctor posts. As the IAU was introduced, agency staff were employed whilst new permanent staff were recruited to maintain the quality of service for patients.'

'We employ agency and locum staff as necessary to cover vacancies and periods of peak demand in order to maintain the quality of service for patients. We appreciate the contribution of these staff to meeting the needs of patients, often at short notice. These staff help to enable us to flex our services to meet changes in demand.'

Have you got a health story? Email adam.gretton@archant.co.uk