A new report has discovered that the demand for agency nurses to work in the NHS is growing.

According to Nursing Times, a report by the health service's in-house temporary staff bank, NHS Professionals, has gathered data from 80 trusts. The report, which has been exclusively shared with Nursing Times, reveals that this mix of trusts used 15% more agency workers during April and June 2010, compared to the previous year. It also shows that the trend is increasing month on month.

This had been labelled a "knee jerk" reaction to budget pressures by workforce experts who say the need to rely on agency nurses is intensified by vacancy freezes and summer absences.

The report states: "Operational experience shows that late release [of shifts] is often due not to operational necessity but financial expediency. Most shift vacancies are visible in advance but not released due to financial pressures."

In fact, trusts are failing to budget for temporary bank staff to fill vacancies such as nurse manager jobs, which means that agency staff are more likely to be used.

Despite some NHS insiders claiming that bank staff were safer than agency staff, this was fiercely disputed by James Buchan, professor of social science and healthcare at Queen Margaret University College in Edinburgh. He said agency nurses should be used because not filling vacant posts was forcing nurses to work additional hours.