Not only can the Government no longer defend the academies programme on the basis of better results than other schools - as explained in the letter from Professor Richard Pring and others (Letters, 29 April) - but academies cannot be defended on the grounds of cost.

They have cost the public purse far more than other schools - see the Public Accounts Committee report from January which stated that more than a quarter “may require additional financial or managerial support to secure their longer-term financial health” and that #163;8.5 million has been earmarked to assist those anticipated to be in financial difficulty this academic year.

A recent letter from the Department for Education introducing the consultation on school funding reform says: “We consider the current system for funding academies to be unsustainable.”

When a school decides to convert to become an academy, it is offered extra money as well as the money it would have had from the local authority, but this is spent on becoming a company limited by guarantee and paying for services from private organisations. In addition, although staff initially maintain their pay and conditions through Transfer of Undertakings (Protection of Employment) regulations, academies have often restructured, requiring staff to re-apply for posts, after which their pay is lower than before.

Senior leaders in academies are being paid more than their equivalents in other schools. This is unfair and means no extra money goes to educating children. Local authorities have less money to support the rest of their schools and academies spend more on helping the private sector make profits.

Melian Mansfield, Campaign for State Education, London.