Five schools have had their Sats results wiped, with the pressure of national tests being blamed for driving schools to cheat.

Four schools in England were stripped of results in English, maths and science, after an official inquiry uncovered malpractice in the national curriculum Sats tests taken by 11-year-olds.

A fifth school had its English results wiped.

The revelations followed warnings from academics, children's charities and teachers that highly pressurised national tests have come to dominate primary education.

The National Association of Head Teachers general secretary Mick Brookes said incidents involving malpractice reflected "the extreme end" of the pressure that schools face to get results.

"We need an assessment system that promotes professional integrity and this one does not," he said.

Mr Brookes criticised ministers for failing to listen to schools' concerns over the high pressure tests.

"The fact that in three weeks' time some children will be rehearsing Sats rather than enjoying Christmas activities is a total indictment of the system and the pressure it puts on people to perform.

"It is absolutely wrong," he said.

Schools Minister Lord Adonis said: "It is unacceptable and unnecessary for any school or teacher to cheat.

"Clearly, five out of over 13,000 primary schools is not at all representative of what is happening in our schools and cannot be seen as any indication of national tests causing increased pressure on teachers.

"We do not accept the view that national tests dominate the primary curriculum - less than 0.14 per cent of teaching time is spent on Key Stage 2 tests.

"National tests help schools ensure that children are progressing and it is vital that children leave primary school competent in the basics, otherwise they will fail at secondary school."

Schools hit by cheating allegations included St Charles' Catholic Primary School in Liverpool and Brockswood Primary School in Hemel Hempstead, Hertfordshire.

The other schools to lose all their results were St Bernadette's Roman Catholic Primary School in St Albans and Springfield Community Primary in Hackney, north London.

William Cowper Primary School in Birmingham had its English results annulled.

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