Inner-city schools which fail to attract large numbers of poor pupils will be the biggest losers in the Government's proposals for a complete overhaul of the way schools are funded.
This week, the Department for Education launched a consultation on school funding, which would see a wholesale redistribution of money across England's schools.
It is the first time in nearly a decade that the Government has considered a fundamental overhaul of school funding. It also plans to make major changes to how academies are funded, which it claims is no longer sustainable.
Under the proposals in the DfE's consultation, some schools in local authority areas that currently enjoy higher rates of settlement, such as Kensington and Chelsea or Camden, both in London, but which have high middle-class intakes, will see their budgets slump.
Primaries and secondaries with high numbers of pupils on free school meals (FSM) will have their budgets sustained by the pupil premium, which provides pound;430 of additional funding per pupil per year. But those that don't will lose out.
Schools that are likely to feel the pinch as a result of the changes include the London Oratory, where Tony Blair's children were educated, and St Mary Abbots Primary, where David Cameron sends his.
According to Malcolm Trobe, policy director at the Association of School and College Leaders, schools in areas of high deprivation but with few poor pupils will come out worst.
"There will undoubtedly be winners and losers as a result." he said. "Inner-city schools with low free school meals will lose out on the (new funding) formula and not get it back in the pupil premium.
"There are going to be some very unhappy people because they are going to be receiving less money, but the question is: do you want a more equitable funding system?" he added.
The DfE plans to overhaul the way schools are funded as it says the current system creates too much variation in how much money schools with a similar intake receive.
According to Department figures, similar primary schools in different parts of the country can see differences of pound;1,300 per pupil, while certain secondaries can see as much as pound;1,800 variation.
The disparity means that similar secondary schools with 1,000 pupils could be pound;1.8 million better or worse off.
In launching the consultation, schools minister Lord Hill said it would result in "fairer funding" across the board.
"Addressing the disparities and inequalities within our school system is a top priority for the coalition Government. For standards to improve, all pupils must get the support they are entitled to," Lord Hill said.
The decision by the DfE to examine the way schools are funded has been broadly welcomed, with heads' union the NAHT claiming it had been campaigning for a rethink for a number of years.
General secretary Russell Hobby said many other governments had "dodged" making wholesale changes to the current funding formula.
"The problem with doing it in the current climate is that it doesn't mean some schools will see a levelling up, but more likely a levelling down," Mr Hobby said.
"That doesn't mean that's the wrong thing to do; it just means it is really going to expose the profession's willingness to share."
The F40, a group of local authorities campaigning for fairer school funding, said it was "excited" by the consultation.
Gillian Hayward, the F40's vice-chair, told The TES: "The Government has highlighted the problems in terms of the unfairness in the system and realises the complexities that are involved in any kind of transition. But we are encouraged by what we have seen."