Concerns are raised about Labour's policy under shadow education secretary Tristram Hunt . The heads of some of Britain’s best state schools today warn of the dangers of a Labour government reversing radical education reforms. In a letter to the Daily Mail, 80 current and former leaders say there is clear evidence that academy-style freedoms are benefiting a generation of children. But they say Labour – and some senior Lib Dems – appear to be threatening to reimpose state controls. The letter, signed by the heads of good and outstanding autonomous schools, was backed yesterday by David Cameron. In it, they claim there is evidence that the most successful education systems benefit from schools with academy-style freedoms. They say such schools are more likely to be ranked ‘outstanding’ by Ofsted and more likely to improve. ‘Secondary schools which have converted to academy status outperform other schools – by a margin of almost 10 per cent,’ they wrote. But the heads expressed alarm at comments by Ed Miliband that Labour would reimpose ‘a proper local authority framework for all schools’. Senior Lib Dems were also accused of suggesting they no longer support freedom for acdemies, which are able to control pay, conditions and the curriculum. ‘This is not the time to stop something that is working to the benefit of so many children in schools,’ wrote the heads. Schools on the letter include Torquay Boys’ Grammar School, ranked in the top 100 for GCSE results this year. United Westminster Schools in London is also on the list, and includes Grey Coat Hospital – where Mr Cameron’s daughter Nancy starts this year. Tom Clark, chairman of Freedom and Autonomy for Schools National Association, which organised the letter, added: ‘Our only concern is that the autonomy which has worked well for pupils stays in place.’ Mr Cameron said yesterday: ‘Ed Miliband would put all this at risk.’ The letter, signed by the heads of good and outstanding autonomous schools, was backed by David Cameron . As the General Election campaign turned to education yesterday, the Prime Minister also attacked Labour yesterday for opposing the expansion of free schools – which are run by groups such as teachers, parents and charities and are outside of local authority control. He said the opposition’s antipathy appeared to be based on a concern that ‘if we set up a good new school, everyone will want to go there’. ‘Yes – that’s the whole point,’ he told the Mail. ‘How can you possibly be against an excellent school setting up another excellent school?’ He accused Labour of being ‘anti free schools’ for suggesting it wants to scrap the scheme. ‘It’s that mindset that says choice, freedom, responsibility, aspiration – that these are things to worry about rather than celebrate,’ he added. The education reforms, masterminded by Michael Gove, have been hailed by Mr Cameron as the most important ‘for a generation’. Ed Miliband has said Labour would ‘have a proper local authority framework for all schools’ We write as current and former headteachers and school leaders of good and outstanding autonomous schools across the country committed to the very best in state education. FASNA — the Freedom and Autonomy for Schools National Association — has helped build a consensus over 25 years which recognises that diversity and self-determination help shape outstanding education. We are firmly committed to the maintenance of current academy freedoms. International evidence shows that the most successful education systems benefit from schools with academy-style freedoms. The freedoms which have come with academy status have helped FASNA schools to improve education for children in our own schools and also enabled us to work better together to raise standards in other schools. The evidence shows that primary schools which have converted to academy status are doing better than other schools — they are more likely to be ranked ‘outstanding’ by Ofsted and are more likely to improve from ‘good’ to ‘outstanding’. Secondary schools which have converted to academy status out-perform other schools by a margin of almost 10 per cent. But as school leaders we are concerned that recent statements from Liberal Democrat and Labour politicians suggest they might not protect all the freedoms which schools and teachers now enjoy and which are helping to drive up standards across the board. Though Shadow Education Secretary Tristram Hunt said that Labour would not ‘go back to the old days of the local authority running all the schools’, Ed Miliband has said Labour would ‘have a proper local authority framework for all schools’. And a Liberal Democrat education spokesman told a recent FASNA conference that he could not support the freedom for schools to vary pay and conditions or to vary the curriculum, and he felt that schools needed local control. Any erosion of school freedoms through local authority or government regulation or overbearing ‘middle-tier’ structures will reduce the capacity of schools to perform well in the future. We call on all political leaders to guarantee that all current academy freedoms, including those relating to pay and conditions and the curriculum, will be maintained after the General Election. This is not the time to stop something that is working to the benefit of so many children in schools. The letter was signed by: . Tom Clark CBE, chair of FASNA, former principal George Spencer Academy, Nottingham . Martin Murphy, headteacher, Arden Academy, Knowle . Richard Vasey, headteacher, Ashfield School, Kirkby in Ashfield . Karen Land, chief finance officer, Aspire Academies Trust, Bovingdon . Steven Chamberlain, headteacher, Barnby Road Academy primary and nursery school, Newark . Corrina Beckett, school business manager, Barnby Road Academy primary and nursery school, Newark . Simon Ascroft, headteacher, Biddulph High School, Stoke on Trent . Steve Phillips, principal, Biggleswade Academy Trust, Biggleswade . Andrew Cliffe, headteacher, Brine Leas School, Nantwich . Nick Law, headteacher, Carre’s Grammar School, Sleaford . Duncan Gauld, headteacher, Christ Church Chorleywood C of E School, Chorleywood . Caroline Anderson, operations manager, Christ the King School, Nottingham . Tony Lamberton, headteacher, Christleton High School, Christleton . Dame Kate Dethridge, headteacher, Churchend Primary Academy, Reading . Tony Parker, director of school improvement, City Learning Trust, Stoke on Trent . Terry Molloy, headteacher, Claremont High School Academy, Harrow . Paul Evans, headteacher, Colyton Grammar School, Colyton . David Hermitt, chief executive officer, Congleton High School, Congleton . Seb Sales, headteacher, Connaught Junior School, Bagshot . Tony Hull, CEO, Evolution Academy Trust Costessey Junior School/Evolution Academy Trust, Norwich . Kieran Earley, headteacher, Devonport High School, Plymouth . Colin House, headteacher, Dove House School Academy Trust, Basingstoke . Sonia Case, headteacher, Dulwich Hamlet Junior School, Dulwich Village . Androulla Peek, executive headteacher, Fleetville Trust, St Albans . John Mirfin, vice chair of governors, Foxwood Academy, Nottingham . Chris Humphreys, headteacher, Foxwood Academy, Nottingham . Fraser Mitchell, principal, George Spencer Academy, Nottingham . Susan Jowett, executive principal, George Spencer Academy, Nottingham . Catharine Darnton, headteacher, Gillotts School, Henley on Thames . Pamela Birch, headteacher, Hambleton Primary Academy, Poulton Le Fylde . Drew Povey, headteacher, Harrop Fold School, Salford . Emma Yates, headteacher, Hayesfield Girls’ School, Bath . Carl Ward, executive principal/chief executive Haywood Academy/City Learning Trust, Stoke on Trent . Mark Knapton, principal, Healing School – A Science Academy, Grimsby . Michael Cook, headteacher, Heckmondwike Grammar School Academy, Heckmondwike . Steve Riches, headteacher, Highams Park School, London . Peter Nutkins, headteacher, Humphrey Perkins School, Barrow Upon Soar . Cathy Longhurst, headteacher, Mandeville Primary School, St Albans . Clare Askwith, acting headteacher, Monkton Infants School, South Shields . Stephen Morales, executive director, National Association of School Business Management . Mark Perry, headteacher, New Waltham Academy, Grimsby, . Peter Beaven, etired headteacher, executive board member of FASNA, Norton Hill School and Somervale School, Radstock . Steve Dunning, headteacher, Olney Infant Academy, Olney . Martin Shevill, ex-headteacher, Ossett Academy & Sixth Form, Ossett . Nick Daymond, headmaster, Parmiter’s School, Watford . David Wilson, chair of governors, Pax Christi Catholic Academy Trust, Nottingham . Kim Barrett, deputy head, Pelham Primary School, Bexleyheath . Sue Darbyshire, headteacher, Platt Bridge Community School, Wigan . Joan Binder, chair of governors and vice chair of FASNA Plume School, Maldon . David Stephenson, headteacher, Plume School, Maldon . Neville Coles, principal, Priory Community School, Weston-Super-Mare . Nick Edwards, business manager, Queen Elizabeth’s Grammar School, Blackburn . Neil Enright, headteacher Queen Elizabeth’s School, Barnet . Kathy Winrow, retired head, Ranelagh CE School, Bracknell . Keith Douglas, headteacher, Rickmansworth School, Rickmansworth . John Leigh, headteacher, Sandbach High School and Sixth Form College, Sandbach . Andrew Fielder, executive principal, Sandy Hill Academy, St Austell . Chris Crook, headteacher, Smallthorne Primary School, Stoke on Trent . Andrew Johnson, executive headteacher, Springwood High School, King’s Lynn . Simon Duggan, headmaster, St Anselm’s College, Wirral . Nigel Fisher, headteacher St Columba’s Catholic Boys’ School, Bexleyheath . Joan McCarthy, headteacher, St John Houghton Catholic Voluntary Academy, Ilkeston . Dame Sue Bourne, headteacher, The Avenue School Special Needs Academy, Reading . Gary Pratt, headteacher The Chafford School, Rainham . Iain Erskine, headteacher, The Fulbridge Academy, Peterborough . Sharon Bruton, chief executive officer, The Keys Federation Academy Trust, Hindley Green, Wigan . Martin Latham, retired headteacher, The Robinswood Academy Trust, Matson . David Hampson, chief executive Tollbar Academy, Grimsby . Jane Aukett, vice-chair of governors, Tollbar Academy, Grimsby . Rosemary Joyce, headteacher, Tonbridge Grammar School, Tonbridge . Peter Lawrence, headteacher, Torquay Boys’ Grammar School, Torquay . Roy Blackwell, clerk to foundation and governors, United Westminster Schools, London - Grey Coat Hospital Foundation . Denham Kite, headteacher, Victoria Dock Primary School, Kingston Upon Hull . Dianne Marshall, executive headteacher, Violet Way Academy, Burton-upon-Trent . Jayne Harrison, school business manager, Violet Way Academy, Burton-upon-Trent . Arthur Goldstraw, chair of governors, Violet Way Academy, Burton-upon-Trent . Lynne Fox, executive principal, Wade Deacon High School, Widnes . Pam Wright, chief executive officer, Wade Deacon Innovation Enterprise Academy, Widnes . Dame Helen Hyde, headteacher, Watford Grammar School for Girls, . Watford Stuart Beeley, headteacher, Wellington School, Altrincham . John Rowan, headteacher, Whirley Primary School, Macclesfield . Tanya Watson, headteacher William Tyndale Primary School, London . Linda Davis, principal, Wistaston Academy, Crewe . Peter Taylor, headteacher, Worth Primary School, Poynton .