Your article “SEN schools take ‘leap of faith’ with academy bids” (11 February) demands decisive and determined action by the Department for Education on two inextricably intertwined issues.

Firstly, admission criteria to special academies must be made clear and reserved for those pupils who have the most severe and complex learning needs. Such pupils are unlikely to profit from the mainstream school curriculum and are, therefore, those for whom separate specialist school placements must be made available if requested.

Secondly, a national funding formula must be established (in addition to the pupil premium) for special academies. Funding must be aligned to the real and increasingly expensive costs of meeting the needs of pupils with severe and complex learning difficulties. The funding arrangements must be simple, transparent and calculated to cover all costs.

Before special academies are to benefit from new freedoms they will first require a little more certainty than that brought about by free market forces.

Ron Babbage, Headteacher, St John’s Foundation Special School amp; College, Bedford.