The private girls’ school in inner-city Liverpool that announced last week it is in talks to join the state sector could be writing itself into the history books.

In the last few days, since news broke of Belvedere school’s plans to scrap fees and become a city academy, several other private schools have been in touch with education officials to explore similar transfer deals. Belvedere could turn out to be the first step in what one government source described as nationalising private education.

The news will presumably delight Andrew Adonis, the education minister largely behind the government’s proposals to reshape the face of schooling in Britain.

But it has horrified some parents at the £6,930-a-year girls-only school in Toxteth. One mum, Yvonne Crawford, told a local paper last week she was “appalled” and feared the school’s ethos and standards would be eroded.

So why is the 125-year-old, 600-pupil school, sited in a series of former merchants’ houses, considering such a radical move?

The answer seems to lie partly in an ambitious experiment that started five years ago. It was then that millionaire philanthropist Sir Peter Lampl agreed that his charity, the Sutton Trust, would (with the Girls’ Day School Trust, which runs the school) bankroll a groundbreaking admissions system. Lampl believes that the best private schools should be opened up to the brightest children — even if they can’t afford the fees.

At Belvedere girls were selected according to their performance in competitive tests and regardless of their family’s finances. The result was that every year saw an increase in the number of girls from poorer homes whose places were paid for by the two trusts. Last year only 30% of parents paid full fees.

Barbara Harrison, chief executive of the GDST, admits that the success of an initiative which cost the two charities more than £2m a year had caused some financial headaches.

“It was more successful than we ever imagined,” she said. “Even with the generosity of Peter Lampl there must be a limit to what we jointly can put into this.”

Under the new plans, which would see Belvedere become a city academy by 2007, the entrance tests would be scrapped and only 10% of girls selected on ability, probably in modern languages.

The task now is to convince sceptical parents that a school which admits all-comers and is paid for by taxpayers can be as good as Belvedere, where this summer 88% of GCSE pupils got As or A*s.

Alison Sherman, the acting head, says that so far no parent is planning to remove a child and Lampl is bullish. “A lot of parents will be getting a very good education for free if this goes ahead,” he said.