understands that at least one recruitment agency that places temporary staff has been advising the heads and senior managers it works with to change their supply teachers' job titles every 12 weeks in order to avoid paying supply teachers permanent staff rates.
Employers found to be breaking the law would face fines of up to pound;5,000 for every claim, as well as compensation to the aggrieved teacher.
"In such instances, schools can possibly be a bit naive . putting themselves at risk from employment tribunals, union action and fines," said Stewart McCoy, strategic operations manager for recruitment agency Randstad Education. Schools must, he said, avoid breaking the law, even if it means suffering financial repercussions.
Indeed, the directive has been widely greeted with anger by employers beyond the world of education. They are, they have warned, extremely unhappy about the potential additional cost, adding that it will lead to less temporary work being offered. Prime minister David Cameron even attempted a last-minute intervention to prevent the directive becoming law, but to no effect.
Supply teachers often receive 20-30 per cent less pay than permanent staff, and schools nationally spend around pound;500 million a year on agency- provided supply teachers.
Heads' leaders are circumspect in their reaction to the new legislation. Brian Lightman, general secretary of heads' union the Association of College and School Leaders, believes that the changes could lead to unintended consequences.
"We recognise that it is important supply teachers are treated with proper working conditions and are not employed on the cheap," Mr Lightman said. "But this new legislation has potential financial implications that, in the context of the current economic climate, may make it more difficult for schools to employ (supply staff).
"The directive could also have an impact on the Government's correct emphasis on continuing professional development, as it will mean, with less supply cover, teachers will not be able to take days out of the classroom."
Classroom unions are, unsurprisingly, more clear-cut in their views on the subject. They have been as one in heralding it as a major victory in the battle to secure equal pay for temporary staff. NASUWT general secretary Chris Keates said the union had been championing a change in the law alongside public services union Unison. She added that it was "outrageous" that agencies were advising headteachers to consider breaking the law. "The ink is not even dry on the new directive and already agencies are looking for ways to get round the new legislation," she said. "Supply teachers already get a pretty raw deal without this sort of thing taking place.
"But I am not surprised. This is what happens when you allow the private sector into the state school system. We will see more and more of these attempts to undermine the entitlements of workers by companies such as these not complying with this legislation."
Whether it is the schools - as employers - or the supply teachers - as employees - that are going to suffer as a result of this directive is not as yet fully clear. But one thing is certain; it's not going anywhere - whether the prime minister likes it or not.
Employers across the board have warned that due to the fragile economy, temporary work could dry up following the introduction of the Agency Workers Directive.
The new EU legislation comes into effect tomorrow and, despite a last- minute attempt to dilute the directive by the prime minister, it could see temporary workers priced out of the market.
Experts have also warned that employers may simply drop temporary staff after 11 weeks in a bid to avoid having to increase their pay in line with permanent workers.