Mick Brookes: We are ruining the best year of primary school

We are delighted that the Sats regime has been relaxed, and that the Government has done away with tests at age 14. We are even more delighted that the arrangements in place for Key Stage 3 mirror precisely the advice sent to the Schools Minister, Jim Knight, in early May. We asked for more emphasis to be given to teacher assessment, for national sampling to be used to gauge progress, and for tests (or other benchmarking) to be used to ensure the validity of teacher assessment.

But we are furious to the point of incandescence that the same changes have not been put into effect at Key Stage 2. Instead, the current regime appears to be more deeply embedded.

The Department for Children, Schools and Families has been left in no doubt that this course of action will lead to a head-on collision with the National Association of Head Teachers on the issue of Key Stage 2 testing unless ways can be found to remove the objections that the NAHT has put forward over the past few years. Children's education is damaged by the high-stakes testing regime.

The Qualifications and Curriculum Authority (QCA) has pointed to the 10 hours-plus spent by 10- and 11-year-olds rehearsing for the tests. This is an utter waste of time, but schools know that it boosts test results.

In the high-stakes environment created by the regime – one year's poor results equals a poor inspection result, which leads to demoralisation and removal of the head – very few schools are prepared to take the risk of not rehearsing. The result of this is the ruination of what should be the best year in primary school.

Many children have complained about having to rehearse Sats in Year 6, when they should be immersed in a rich and broad learning experience. I have even heard of some schools that have curtailed Christmas activities for 10- and 11-year-olds because they get in the way of Sats preparation. In addition, the enormous time it takes to mark all these papers leads to a huge increase in workload for teachers.

Now, we are not advocates of anarchy. The NAHT is wholly in support of assessment. We are saying that is the wrong sort of assessment. Sats are not a qualification, and yet one mistake made by the child in the highly charged atmosphere of a 45-minute test will mean writing off four years' progress. I spent almost 30 years as a school leader, and there is no way that I would sanction sloppiness in the assessment of pupil progress. Neither would the 28,000 members of the NAHT.

Because of the complex nature of the logistics of marking, communication and security, the tests have to be taken in the first half of May, a full two months before the end of term. If schools were trusted to make their own assessment – and if they are in Key Stage 1 and Key Stage 3, then why not in Key Stage 2? – it would give children the opportunity to make greater progress. At present, anything achieved after mid-May is not recorded or reported.

We are assured by the Department and the National Assessment Agency that the tests are reliable. We disagree with this analysis and we are conducting research to test our anecdotal evidence suggesting that there is a one in five chance of getting the wrong grade in the closed answer tests (maths, science, comprehension) but a one in three chance of getting the wrong grade in writing. If our research confirms this, how can we be demonstrating national achievement on such a bizarre basis?

We are concerned that our colleagues in secondary schools appear to have little faith in Key Stage 2 tests. Most children are tested again when they get to Year 7 as teachers are not convinced that the scores they have received are reliable. So we feel the Key Stage 2 tests spoil the education experience in Year 6 and turn some children off education at a very early age. It is a hugely bureaucratic system that distorts the curriculum, demotivates staff and misleads the public.

We are not alone in this; we know that we have the support of parents and governors. The Government has missed a real opportunity to abolish Sats at 11. The combined weight of parents, governors and education professionals must make a difference.

The writer is general secretary of the National Association of Head Teachers