HUNDREDS of unregistered schools — many of them faith schools — have sprung up across Britain, putting thousands of chil­dren at risk of “harm and indoc­trination”, the chief inspector of OFSTED, Sir Michael Wilshaw, has warned.

Sir Michael said that the 100 schools so far discovered by his newly established team of inspectors were only the tip of the iceberg. In a letter to the Education Secretary, Nicky Morgan, he said: “There are many more children hidden away from the view of the authorities in unregistered schools across the country than previously thought.”

Children in the schools were at “significant risk of harm and in­­doct­­rination”, he said.

About a third of the schools were Islamic, and a sixth were Jewish or Christian.

Seven warning notices have been issued by his team of inspectors to schools in London, Wolverhamp­ton, Birmingham, Luton, and Staf­fordshire.

Any school offering 20 hours of lessons a week must be registered. Unregistered schools are those that operate outside the supervision of the Department for Education, local authorities, or OFSTED inspections.

Sir Michael set up a team of inspectors in January to assess the extent of illegal schools. “What we have found so far is likely to represent only a small proportion of the illegal schools operating across the country,” Sir Michael said. “Inspectors are hear­ing about sus­pected new cases every week”.

In his letter to Mrs Morgan, he said that there was “a clear link between the growth of unregistered schools and the steep rise in the number of children recorded as being home-educated in England over the past few years.”

Many of them, he said, “are un­­scrupulously using the freedoms that parents have to home-educate their children as a cover for their activities. They are exploiting weak­nesses in the current legislation to operate on the cusp of the law. Many are charging parents thou­sands of pounds to send their children to these unregistered schools. . . Many are providing a sub-standard education.”

The British Humanist Society this week launched a website, Faith Schoolers Anonymous, for people to “whistleblow” on faith schools. A pupil at a Jewish school has posted a comment on the site, saying that the school “crippled its students by denying them the education which they had a right to receive and preventing them from flourishing into active members of society”.