Schools are right to refuse to introduce the workforce agreement if they fear it will lower educational standards, the director of the Government’s primary strategy has said.

Kevan Collins said that while he supported the deal, it should not be allowed to undermine gains made in primary education in recent years.

The TES revealed last week that North primary school in Colchester, Essex, was refusing to implement the deal, which guarantees teachers 10 per cent of their time away from the classroom for preparation and planning because it was concerned it would affect standards.

Mr Collins said: “I have got to say that the school has absolutely the right interests of its children at heart. They need more support to make this work.

“Schools want to put the agreement into place, but they want to do it without jeopardising the quality of the educational experience for their children.”

Using teaching assistants to support less able pupils had led to dramatic improvements in their work. In a Leeds university study, 85 per cent of children on a literacy support programme achieved level 4 or above against their teachers’ expectations in Year 5.

But with classroom assistants forced to cover for teachers, projects like this could disappear, Mr Collins said.

He was speaking after a conference in Birmingham for about 1,000 primary strategy consultant leaders, headteachers recruited by their local authorities to help other schools to speed up children’s progress.

A succession of headteachers challenged Derek Twigg, the education minister, on subjects ranging from the workforce agreement to funding.

One headteacher of a small primary school in Cumbria spoke about her struggle to implement the agreement when she already had to spend 80 per cent of her own time teaching.

Mr Twigg said: “I don’t disagree that it’s difficult. We have recognised that and are trying to make it better.”

Last week Ralph Tabberer, chief executive of the Teacher Training Agency, which has overall charge of the workforce reforms, admitted that some schools would not meet the September deadline of allowing teachers 10 per cent planning, preparation and assessment (PPA) time, but said they would not face sanctions.

Classroom teacher unions have said that the deal is statutory and schools cannot opt out.

The National Association of Head Teachers will hold an extraordinary general meeting in London on March 16, when members will decide whether to withdraw from the deal over funding.

And next Friday a group of Nottingham primary heads will consider sending children home early so that they can implement PPA time. They will also discuss whether to set deficit budgets or refuse to implement the deal.

Philip High, head of Radford primary in Nottingham, has written twice to the Government on the issue but says he has yet to receive a straight answer.

Mick Brookes, a candidate for the NAHT leadership, this week said that the association should withdraw if it meant the Government got the message that more funding was needed.

But David Hawker, his opponent and the NAHT council’s official candidate, believes the association needs to stay on board so that it can argue its case at the highest level.