John Hayes is head of Fairlands Primary School in Stevenage, Hertfordshire.

I believe that the tests inevitably lead to 'teaching to the test' - they have restricted the curriculum. The publication of league tables is damaging to children's education.

The main indicator that Ofsted use when preparing their evidence before an inspection is the Sats results, with this notion that every school must be above average - and that being below average is taken as a lack of success in the school.

We only test in English, maths and science, so we focus a large part of the teaching day on those subjects.

And if there are going to be national league tables which supposedly indicate to parents how good schools are, you would be a fool not to try to increase your results.

But the main issue is that the tests do not help the children to learn, they are simply a benchmark the government uses - it's applying an industrial model to schools.

Results go up and down depending on the children. They are individuals and they differ from year to year.

We value what we measure and what's measurable, and that which we don't measure we don't value as highly - and I think that's highly negative.

Do parents want the information results provide?

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We feed them that information - but we don't tell them about other aspects of what we do to help the whole child.

We are not opposed to testing and assessment. We do testing constantly. Testing which is useful and diagnostic is essential to good teaching and we want that to continue.

As for the practicalities of a boycott: assuming NUT head teachers take it up, the test papers won't be distributed to teachers.

Members who are teachers will say they are taking industrial action and refuse to administer the tests.

But it's also about spreading the word to parents.

No parents I have ever spoken to think Sats are a good thing. They talk about how it stresses the children.