The backlash in the independent sector has been under way for a while. Behind the scenes, a number of major independent schools have quietly questioned the idea of sponsoring academies in the maintained sector.
Earlier this week, however, the Girls' Schools Association (GSA) challenged the idea further than any other organisation from the independent sector has to date.
Delegates at the Bristol conference of the GSA, whose members include St Paul's Girls' School in London and Roedean in Brighton, heard their president Helen Wright (pictured, left) express doubt that independents sponsoring failing state schools - in effect taking them over and running them themselves - is the right way to help out.
"We've had lots of discussions with (schools commissioner) Liz Sidwell about primary schools in special measures," Dr Wright told TES. "But is sponsorship necessary to change people's lives? To me, partnership is the most important aspect of it all."
Dr Wright, who is also head of the #163;29,000-a-year St Mary's School in Calne, Wiltshire, was speaking in response to the establishment of the Primary School Academy Group, an initiative unveiled by the Headmasters' and Headmistresses' Conference (HMC) in September to encourage top independent schools to sponsor underperforming - or "below-the-floor" - primary schools.
In the aftermath, some of the best-known schools of this kind - including Harrow, St Paul's, Manchester Grammar and Dulwich College - said they would actively consider the idea of setting up primary academies.
"We have got a number of schools that have expressed serious interest in sponsoring an academy," David Levin, headmaster of City of London School and chair of the new HMC group, said at the time.
At the end of the summer, prime minister David Cameron and education secretary Michael Gove even held a "summit" at 10 Downing Street, at which high-profile independent-school heads were encouraged to become involved in sponsoring academies.
But it is clear that Dr Wright has serious doubts. "You can't go marching in, saying 'We're here to sponsor you'. You have to build relations and it has to be mutually beneficial, otherwise it will cause resentment."
Despite the ministers' appetite for the programme, Dr Wright said the sector would not be bullied. "I don't feel pressurised and I think the independent sector is perfectly capable of standing up for itself."
Dr Wright said as much emphasis should be put on independents "continuing and developing existing relations with the state sector". She also dismissed fears that some of her members were under pressure from the newly established free schools, and added: "A tremendous amount of bureaucracy comes with that. Are they truly independent?"
She did not stop with the Government's academy programme. She also waded into the debate over university admissions and whether offers ought to be skewed towards pupils applying from state schools. "Universities will not take on people who don't make the grades," she said. "It is not the role of universities to make up for the inadequacies of earlier schooling."
Dr Wright added that it was unlikely that pupils from independents would be squeezed out by universities under pressure to enrol children from state schools. "We know our students and match them. Independent schools make the best A-level predictions. We as a sector have always made sure people aren't going to university for the sake of it," she said.