Though children have to be educated, there is no legal requirement in Britain for them to attend school. The progress of children at home may be monitored at intervals by the local education authority.

Home teaching groups claim the number taught at home could soar to 150,000 by 2015, equivalent to one child in 30.

Mike Fortune-Wood, of Home Education UK, a website that provides advice on home schooling, said there was a “quiet revolution” going on. “People find that at home they can provide their children with an education far better suited to their individual needs,” he said.

Janey Lee Grace, a Radio 2 presenter and mother of three, teaches her two older sons, aged five and six, at her Hertfordshire home. She relies on a network of like-minded parents, informal tutoring groups and an organisation called Naturekids, which stresses the link between learning and nutrition.

“I think the school system fails most kids,” she said. “It’s fine if you want to be in the army, but not for most people who are more individual.

“I know a home-taught 11-year-old who is taking her maths GCSE. She will take the rest of her GCSEs at the normal age, but because she is good at maths she is going at her own faster speed.”

In the next academic year parents teaching at home will have the further support of the country’s first internet secondary school. The £165-a-month online school is being pioneered by Paul Daniell, 42, a senior physics teacher in south Wales.

It will use the internet and conference-call technology to offer GCSEs in seven core subjects. Teachers will give morning classes online to small groups and set them work for the afternoon under parental supervision.

To date, more than 40 children have been signed up to the “Inter High School”, which has three teachers. Numbers are expected to grow, with interest from families abroad and even teachers in conventional schools who wish to use the lessons.