The Workload Agreement tries to cut administration for teachers

The National Association of Head Teachers (NAHT) will vote at its conference in Cardiff on whether to pull out of last year's deal unless schools get more cash.

The deal guarantees teachers time away from classrooms and cuts working hours by increasing the role of assistants.

The union says there is not enough money due to last year's funding crisis.

'Fear'

It says some schools were forced to sack their classroom assistants and will debate the issue on Sunday.

The Workload Agreement puts tasks like taking the register and photocopying in the hands of classroom assistants.

It was signed a year ago by all the unions except the National Union of Teachers.

The agreement is being phased in over three years.

NAHT general secretary David Hart has urged delegates in Cardiff not to vote for withdrawal, as that would leave primary schools without a voice in how the agreement should be implemented.

The NAHT has 85% of primary heads in its membership.

The government pledged �1bn from the education budget for the agreement.

The NUT stayed out the agreement because it is opposed in principle to allowing classroom assistants to take lessons in teachers' absence.

On Saturday, NAHT president Rona Tutt told the conference teachers "lived in fear" of disruptive pupils.