The NUT even succeeded in clearing its self-imposed hurdle of having more than two-thirds of the eligible membership support the action. Of 140,000 ballot papers sent out, 97,500 were returned, with 94,000 voting for the boycott - 67 per cent of the union's electorate.
Doug McAvoy, the union's general secretary, said the Government needed to understand that those teachers 'are not expressing a view because of their political feelings, nor because they are militants, but because they are teachers who want to teach'.
He urged John Patten, Secretary of State for Education, to suspend this year's tests immediately, and negotiate a reduction of the teachers' workload. He predicted that, with all three large teacher unions now boycotting, tests would take place 'in only a handful of schools'. Even the results of tests for seven-year-olds, which had already been completed in many schools, might not be reported.
Mr Patten said he deeply regretted Mr McAvoy's unwillingness to advise his members to call off the boycott, in the light of his Commons statement on Tuesday reducing the scale of next year's tests, and the wish of Sir Ron Dearing, chairman of the curriculum and testing authorities, that he should have results from this year's tests to inform his review of the curriculum.
Mr McAvoy said Mr Patten had done nothing to ease teachers' anxiety about the nature of the tests which he intends to hold in English, maths and science, nor had he responded to parents' rejection of tests for seven-year-olds, or their opposition to league tables of results.
Nigel de Gruchy, general secretary of the National Association of Schoolmasters/Union of Women Teachers, welcomed the NUT ballot result, but urged all the unions implementing the boycott to be 'very clear' that its objective was to reduce excessive workload.
'Recent comments and literature emanating from the NUT might be taken to imply that it is more concerned with the educational, philosophical and political aspects of testing, which cannot form the basis of a legitimate trade dispute,' he said.
Peter Smith, general secretary of the Association of Teachers and Lecturers, accepted that some teachers would carry out tests for 14-year-olds in maths and science, and that some of those for seven-year-olds had already been completed. But he said he believed Sir Ron would be provided with evidence on those tests only if he promised teachers that they would be used for no purpose other than his national curriculum review.
Poor literacy and numeracy among children are closely linked to parental ability and income, according to a report yesterday from the Adult Literacy and Basic Skills Unit.
Nearly three out of four children with reading problems have low-income parents who also report reading problems. Where parents had numeracy difficulties, no school qualifications and low income, four out of five children were in the lowest scoring group for maths or reading.
Peter Davis, chairman of the unit, said: 'We need programmes which 'teach the mother, reach the child'.'Reuse content