The European Working Hours Directive (EWTD) is responsible for a significant increase in the NHS's spending on locum doctors, it was reported in The Times on 10 November 2010. The Directive, which introduces a 48 hour limit on a doctor's working week, means that it is increasingly difficult for trusts to adequately fill their rotas with permanent staff and they are having to plug the gaps with temporary staff and locums. Figures provided by the Royal College of Surgeons indicate that the sums involved to fund these temporary doctors and locums are huge.

Of more concern, is the impact of the arrangement on the continuity of patient care and patient safety. Locums may require extra supervision if they are unfamiliar with hospitals, procedures and other staff. Reference was made to a review by John Collins of the University of Oxford who found that, increasingly, junior doctors are being left in charge of units with insufficient supervision because of the effects of the EWTD.