a tests boycott came closer this week as Britain’s biggest teaching union announced its timetable for action.

John Bangs, the National Union of Teachers’ head of education, said that the industrial action would not just involve the administration of the tests in May, but would take in all activities surrounding the tests, including practice exams and “teaching to the test”.

A groundswell of opposition to the testing, targets and tables regime built up over the Easter teaching conference season this year. But only the NUT voted for a boycott, with the leadership of the other two main classroom teacher unions expressing fears about the legality of such action.

Mr Bangs said: “We would not go into a boycott if we did not think it would be legal.” Charles Clarke, Education Secretary, attempted to take the heat out of the situation last month by scrapping national targets at key stage 2 and placing more emphasis on teacher assessment at KS1.

But the NUT argues it has not done enough. “It is a real botch,” said Mr Bangs. “If Wales has had the courage and vision to go for a full review of the system, then why can’t this Government?

“It is about trusting teachers and I am afraid the Government cannot quite manage that.”

The NUT plans to begin its campaign with a consultative survey of all members at the beginning of next term, in an attempt to unite them behind the cause.

Material will also be sent out to members, promoting the work that teachers could be doing when they are no longer preoccupied by tests, targets and tables.

The union says its existing industrial action over bureaucracy would continue to apply to the additional workload related to tests during the autumn term.

A formal ballot on the tests boycott would take place before Christmas, with the action expected to begin as soon as pupils returned for the new term.