Government interference in education and the imposition of national tests deny children a well-rounded education

Ministers are stripping primary school children of their basic human right to a well-rounded education, a teachers' leader warned today.

Christine Blower, general secretary of the National Union of Teachers, said national tests for 10- and 11-year-olds, formerly known as Sats, contravene the United Nations Convention on the Rights of the Child.

Under the Convention, which Britain signed in 1991, children are entitled to a broad education which develops their "personalities, talents and abilities to their fullest potential".

Blower told the NUT annual conference in Liverpool that Sats only gave children the right to pass exams, not the right "to be educated in the round". They reduced children to "little bundles of measurable outputs trained in a mechanistic model of education," she said, repeating words used last month by the children's commissioner, Maggie Atkinson.

Blower said: "The NUT says 'yes' to risk-taking and exciting approaches to learning and 'no' to children as little bundles of measurable outputs."

The NUT – the biggest classroom union in England and Wales – is balloting headteachers and their deputies over whether to "frustrate the administration" of the maths and English tests. Another union – the National Association of Head Teachers – is also conducting the ballot. The unions say they are confident that heads will vote to boycott the tests, which are sat by 600,000 children. Their boycott would take place on May 10, days after the next government came into power.

Teachers want ministers to abolish the tests because they argue they are used to compile "meaningless" school league tables. The tables unfairly stigmatise schools with the most challenging pupils, and turn children's last year of primary school into a repetitive drill for the tests, they say. They want to see Sats replaced by teacher assessment and would accept a system in which only a sample of children were tested.

The ballot ends on April 16.

Labour and the Tories have pledged to keep Sats, although Labour is considering moving to more teacher assessment and the Conservatives argue the tests should be more rigorous and could be sat by pupils in their first year of secondary school.

Blower told teachers: "Together we can ensure that it is teacher assessment… that informs parents and children how they are doing in school and together we can end league tables and Sats."

Her comments come as MPs on the cross-party schools select committee today published a report that came to the same conclusions.

"The way that many teachers have responded to the Government's approach to accountability has meant that test results are pursued at the expense of a rounded education for children," the report – From Baker to Balls: the foundations of the education system – said.

Sats stigmatise and undermine struggling schools by publishing their raw results and dissuade teachers from inventing creative lessons, the report argues. "A better approach would be for the government to place more faith in the professionalism of teachers and to support them with a simplified accountability and improvement system which encourages good practice. If pupils' attainment is used to judge teachers and schools, teachers cannot be expected to be dispassionate assessors of that attainment, and teaching to the test is a likely consequence. We therefore have reservations as does Ofsted⎯about the effects of national testing in concentrating teachers' efforts upon certain areas of the National Curriculum."

The MPs warned that the government was placing pressure on schools to follow non-statutory guidance and said local authorities needed to keep a closer eye on how teachers were spending school budgets.

They said: "Local authorities should be more involved with monitoring, supporting and, where necessary, intervening in school budgets and finance. It is indefensible that the expenditure of such vast sums should attract so little scrutiny. We do not advocate an erosion of schools' autonomy, but we consider it important that the correct level of financial support is available to them in order to derive maximum value for money from the schools budget."