"Bare bones" private schools could be set up for as little at #163;2,000 a year per pupil, by employing inexperienced teachers, increasing class sizes and even replacing staff with technology, an academic has said.
Professor James Tooley says the schools could bring private education within the reach of even the most poorly paid parents dissatisfied with their local state schools.
Average independent fees stand at around #163;10,000 a year for day pupils, rising to nearly #163;30,000 at top boarding schools.
But Professor Tooley, of Newcastle University, said extra cash to plug funding gaps at the new budget schools could be scraped together through commercial sponsorship of facilities, such as soap companies advertising in school toilets.
He claimed the model, based on the popularity of low-cost schools in the developing world, could appeal to parents in areas where what the professor described as "terrible and disgusting" oversized state schools still exist.
Professor Tooley, who is well-known for his research on private schools for slum-dwellers of India and Africa, told the Festival of Education at Wellington College last weekend: "You can create a very low-cost school for #163;1,500 to #163;2,000 a year; it could be a business model for this country.
"I would love to see a school opening, using a lot of technology, as it is cheaper here than in the third world."
He told delegates the #163;6,000-a-year fees charged by existing budget chains such as Cognita and the New Model School Company were good, but claimed that "you can go even lower".
He added: "Our view of private education is coloured by the likes of Wellington College, but you don't need all these overheads.
"You don't need to have the best maths teacher here; using technology, you can have the best maths teacher at Harvard."
Speaking to The TES, Professor Tooley admitted that state schools had cornered the market in many areas, but he added: "I know areas of Newcastle, such as Byker, Walker and North Shields, where the schools are still terrible, disgusting places. People get lost there; there are low expectations.
"The small size of the private school and the young, enthusiastic teachers could be its selling point."
Professor Tooley said parents would pay "per day" fees, to spread all costs, including food and uniform. This would work out at roughly #163;10 a day per pupil.
"Based on minimum-wage full-time earnings of #163;12,000 a year, parents would have to give a sixth of their income," he said.
He said entrepreneurs needed to realise there was money to be made out of the system, if they created chains.
However, his claim that a school can be run for as little as #163;2,000 a year per pupil has been disputed by many in the private sector.
Robert Whelan, founder and director of the New Model School Company, which runs three low-fee private schools in London, said he had found it difficult to charge less than #163;6,000 a year.
He said: "We have low accommodation costs for our schools as the buildings are rented, but there are heavy compliance costs here in terms of Ofsted, health and safety, and they are not optional."
However, he added that costs could be saved on class size. "We've an average size of 20, but if you drove that up to 30 it would make a huge difference," he said.
JAMES TOOLEY: PRIVATE PASSIONS
Professor James Tooley started his career as a maths teacher in Zimbabwe
- He is currently professor of policy studies in education at Newcastle University
- He is chair of two low-cost school chains: Omega Schools in Ghana and Empathy Learning in Hyderabad, India
- In 2002, his book The Miseducation of Women was published. In it, he argues that girls should be allowed to embrace their domestic destiny
- In 2009, another book, The Beautiful Tree, examined budget private schools in developing countries.