The National Union of Teachers called off its planned boycott after less than a third of its primary members voted to take action. And a TES poll found just 37 per cent of primary staff back a boycott.

The ballot result was a relief to the Government which had feared the NUT action would be politically damaging. Ten years ago, a test boycott won widespread support from teachers.

NUT general secretary Doug McAvoy said: “Ten years ago, teachers were collectively against the regime. Since then they have worked with it and it has become something of a bad habit.”

For the action to go ahead, more than half of the 103,729 NUT primary members in England had to back it. But only a third of papers were returned. The union said the result offered no comfort to ministers - as 86 per cent of those who did vote wanted industrial action.

Mr McAvoy said it had been hard to persuade those not involved in testing to vote.

Education Secretary Charles Clarke said: “A boycott could have been very disruptive. It would have let down pupils and parents. National testing helps drive improvement in all schools.”

David Hart, general secretary of the National Association of Head Teachers, said: “There is no overwhelming body of support for a boycott of tests for 11-year-olds.”

A TES poll of 252 primary teachers by FDS International found 37 per cent would be willing to stop preparing seven or 11-year-olds for tests or marking their papers but 33 per cent would not. Just under half the 127 NUT members in the poll supported a boycott.

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