Around three-quarters of Bradford primary schools are boycotting national examinations for 11-year-olds, according to teaching unions.

Head teachers are not administering SATs (Standard Assessment Tasks) tests to Year Six pupils at more than 90 of the district’s primaries, said Ian Murch, Bradford branch secretary of the National Union of Teachers.

Senior members of the NUT and the National Association of Head Teachers are taking action to show the strength of feeling for abolishing the Key Stage Two tests, which were due to be sat in English and maths from yesterday.

Bradford Council admitted it did not know how many schools were involved in the boycott. Mr Murch said: “It will be a substantial majority of schools that are involved. We don’t know how many exactly but more than 90 schools have been supportive of action.”

Sue Naylor, Bradford branch secretary of the NAHT, said: “At the end of the week it will be clear how many schools have joined in by the number of exam papers being sent back. The vast majority of Bradford primary schools are involved.”

Cindy Peek, Bradford Council’s deputy director of Services to Children and Young People, said governing bodies were not obliged to inform the local authority if they were boycotting tests.

Many educationalists insist SATs are a crude measure of ranking schools’ performance in league tables.

Michael Latham, head at Newby Primary School, in West Bowling, a school with two successive ‘outstanding’ Ofsted reports, said he had joined the boycott. “After over 20 years in headship in three schools this is the first time I have even considered taking any form of action against Government policy,” he said. “SATs have contributed to significant improvements to standards in English and mathematics since the early 1990s but the time is right for Government and schools to seek a better match between curriculum expectations, testing methods, reporting attainment and school effectiveness.”

Sara Rawnsley, head of Princeville Primary, in Shearbridge, Bradford, is not holding the exams. She said: “We need to be brave and bold. I don’t believe in SATs and that a 45-minute test can assess everything a child can do.”

Wahid Zaman, head of Atlas Primary School, in Manningham, resisted the boycott, saying: “I see some merit and I also see some drawbacks but it is a standardised measure of how our children are achieving and the results are an independent measure that we can hold up to Ofsted.”