ALL but one of the largest English unions this week signed a far-reaching reform programme to cut teachers’ workloads, but headteachers are threatening to pull out if the Government fails to provide the cash.

With the exception of the National Union of Teachers, all unions will now work jointly with ministers until at least 2006 to to cut working hours and offer more personalised learning for pupils.

Twenty-one months after industrial action by the two biggest classroom associations forced the Government to review workloads, unions and employers signed a joint agreement with ministers on Wednesday.

The 22-page document sets out a string of changes, including the transfer of routine administrative tasks to support staff, guaranteeing teachers time out of lessons to do marking, and cutting the time they must cover for absent colleagues.

A 12-member panel of heads - dubbed the “juke-box jury” - will issue termly reports on the Government’s progress in cutting bureaucracy. And all parties will meet monthly to assess how the reforms are being implemented.

But the NUT is being excluded after its executive voted unanimously to reject the proposals over the Government’s decision to allow a new breed of “super assistants” to cover for teachers.

As representatives of other unions and teachers’ employers travelled to the Department for Education and Skills in Westminster for a signing photocall, the NUT invited journalists to a “non-signing” lunch nearby.

The National Union of Teachers took out another advert in The TES this week to attack the agreement. But it ruled out any immediate industrial action against the use of assistants to cover lessons.

Instead, general secretary Doug McAvoy pledged to mount a campaign to get teachers and parents to persuade heads not to use support staff as “cheap” substitutes.

The union is still urging ministers to give it a place on the group which will monitor the agreement’s implementation.

In an interview with The TES, school standards minister David Miliband pledged that teachers would see lighter workloads by 2006, as well as becoming part of an “empowered profession” in which thousands of support staff would help deliver learning better tailored to pupils’ individual needs.

Although some with very heavy teaching loads would see them reduced, most teachers would get the “space, time and the support staff to concentrate on teaching”.

However, Mr Miliband has rejected a suggestion from the Government’s own advisers to set targets for working hours, which he said would be “arbitrary and artificial”. He was disappointed that the NUT had not signed up but said there was now a “broad and determined coalition” for change.

He rejected the NUT’s claims that new senior assistants would be teachers on the cheap. Schools would not let standards suffer. “What head is going to do wrong by their pupils?” he asked.

But Mr Miliband has now become embroiled in a row over his claim that pound;1 billion has been set aside to fund the reforms. He used the figure last week in a speech to the North of England education conference.

David Hart, general secretary of the National Association of Head Teachers, condemned the total as “meaningless”. He said that schools would have to fund the bulk of the workload reforms out of general budget increases.

The NAHT says that it will pull out of the talks if heads find they do not have enough cash to back the reforms, which are being introduced amid fears that schools in some areas of the country are facing a budget freeze.