Over the centuries, Eton College has educated the children of wealthy families from all over the world. But the prestigious private boarding school has come under fire for turning its attention closer to home, backing a government-funded boarding school moulded in its own image.

The historic move attracted the ire of teaching unions, which complained that the new school would cater for an elite, rather than the majority of local families. But one of the key players behind the project has now hit back.

Simon Dudley, banker and deputy leader of Conservative-led Windsor and Maidenhead Council, insists that it will be “a comprehensive school and it’s going to have a very broad social mix”.

“You could have a millionaire’s child next to a child whose parents are on benefits,” he said.

Mr Dudley, whose son recently left Eton, said the new school, Holyport College, would “actively target” local primary schools in areas of deprivation. The social mix has been “hardwired” into the admissions policy, he said, as 20 per cent of children have to be eligible for the pupil premium, which provides extra money for children from disadvantaged homes. The proportion of children qualifying for the money in the borough overall is just 7 per cent.

But in defending the school, which will be in the leafy village of Holyport, near Maidenhead, Mr Dudley admitted it would also provide “an answer” for parents who had been priced out of the independent school market. Boarding fees at the school will be #163;11,500 a year, compared with more than #163;32,000 at Eton.

Holyport, due to open next year, will eventually cater for 500 pupils: 225 boarders and 275 day pupils. Of those, 28 pupils will be on boarding bursaries and a further 21 vulnerable children will be paid for by local councils.

Eton’s support for the school as its “educational sponsor” is its second foray into state-funded education: it is also a key backer of the London Academy of Excellence, a sixth-form college in East London that prepares pupils for top-flight universities.

Like many other top private schools, it has been keen to emphasise its charitable foundation, after pressure from the government for elite fee-paying schools to support the state sector. Other private schools, including Dulwich College and Wellington College, have backed state-funded academies.

About 16 per cent of children in Windsor and Maidenhead are privately educated, more than twice the national figure. In 2008, 11 per cent were recorded as attending selective grammar schools in other counties.

Mr Dudley said parents had responded positively to the prospect of the Eton-sponsored school, with 750 families already pre-registering their children, some as young as two years old. Those who win places will be able to use Eton’s sports facilities and attend scholarly activities laid on by the private school.

Tony Little, headmaster of Eton, said that although the school was being set up in a “middle-class area”, he felt this was an advantage. “If you’re offering real support to people in care or from disadvantaged backgrounds it is good if the broad tone of the school is aspirational and there are supportive families,” he said. “We don’t want the school to only be about looked-after children; you want it rich and mixed.”

But Hank Roberts, national president of the ATL teaching union, said private schools “should not be getting involved in party political education matters” by supporting free schools and academies. Private schools wanting to support disadvantaged young people should do so by increasing bursaries and opening up access to their facilities, he said.

Open the gates

Holyport College will occupy the former site of Holyport Manor special school. Refurbishing an existing period house and adding new buildings and sports facilities will cost #163;15 million.

The school is within walking distance of the Royal County of Berkshire Real Tennis Club, where Prince Edward was said to have first met his wife Sophie Rhys-Jones, now the Countess of Wessex.

By 2020, the school aims to have 225 boarders and 275 day pupils. Twenty-eight pupils will receive boarding bursaries and 21 pupils will be in care or on the edge of care. They will be paid for by local authorities.

The timetable will follow a typical private school day, with all pupils completing their homework on the premises.

The school will open in September 2014.