The Government is backing the development partnerships between schools and higher education institutions to organise such training. The partnerships allow student teachers to spend more time in classrooms. In return, the institutions pay the schools to support their contribution to training the students.
The DFEE issued a circular earlier this year which stated that teachers were contractually obliged to undertake ITT duties if so required, and governing bodies could use some of their budgets to pay staff for the extra work involved, depending on the amount of cash received from the higher education institutions.
But the NAHT says there is nothing in teachers' statutory conditions of service to suggest they must engage in work to do with training student teachers. Such duties, it says, are part of the provision of higher education, not primary or secondary education.
It also claims that the higher education institutions are so far not paying schools enough to join initial teacher training partnerships, and that it is illegal to ask schools to contribute to the costs from their own budgets.
The NAHT has obtained leave from the High Court to apply for a judicial review of the DFEE's circular, though a hearing date has not yet been fixed.
David Hart, NAHT general secretary, said: "We have positively advised our members not to top up grants from higher education institutions because we don't think it's legal. Raiding money which is there for the education of pupils to provide education for student teachers is just not on.
"The point of this whole exercise is to force higher education institutions and therefore the Government to rethink funding arrangements for ITT partnership arrangements and prevent employers from following the DFEE line which says teachers can be directed to participate in ITT.
"There are real grounds for believing that the Government is encouraging the delivery of ITT on the cheap by emphasising the fact that school budgets can be used to subsidise the cost of ITT incurred by schools. It is vital that the law should be made clear as soon as possible," he adds.
A DFEE spokeswoman said Education and Employment Secretary Gillian Shephard believed that while initial teacher training activities were not directly the province of primary and secondary education, they were incidental to it, and therefore fell within the scope of the School Teachers' Pay and Conditions Act 1991.
"She also believes that funding from a school's own budget can be used for activities which fall within the scope of the 1991 Act and the School Teachers' Pay and Conditions document," the spokeswoman added.