Thousands of casual workers may have won the right to holiday pay, maternity leave, sick pay and other employee benefits following a ground-breaking judgement by the Court of Appeal at the end of March. The ruling means that part-time workers without a job contract who work on an 'as required' basis could have the same rights as full-time staff.

But lawyers will be studying the judgement to see how it reconciles with an earlier Appeal Court ruling that bank nurses are probably not employees where there is no duty to accept work and the employer is not obliged to offer it. A spokesperson for Unison said: 'We think this new ruling re-opens the debate.'

In the latest case, brought against National Power, three judges, by a twoto-one majority, found that two women guides who showed visitors around power stations were employees, overruling earlier decisions by an industrial tribunal and the Employment Appeal Tribunal that they were not. The judges sent the case back to the industrial tribunal for a decision on what terms should have been incorporated into the women's employment contracts.