Headteachers have launched a blistering attack on government plans to allow new grammar schools, saying selection in Kent erodes children’s confidence and the system should be scrapped.

A joint letter from 32 headteachers of non-selective schools across the county says there is no evidence to support the government’s claim that selection improves standards.

They say there is an urgent need to highlight “fundamental philosophical and systematic flaws” in the proposals for a new generation of grammars outlined by Theresa May.

The letter has been sent in response to the government’s consultation on its plans, outlined in its White Paper “Schools that Work for Everyone,” which ended last week.

It says the government should consider the impact of its proposals on children who do not go to one of the county’s grammars in the face of a lack of evidence that selection benefits all students.

It asks: “What does the selective system achieve in Kent? It certainly serves to erode self-confidence, to limit aspirations and develop a culture of ‘second best’ that good leaders in non-selective schools then spend time undoing so that they can unlock the students’ true potential.”

It goes on to say the gap between disadvantaged children and their peers in Kent is one of the widest in the country.

“The very existence of a two-tier selective system is the biggest cause of this inequality.”

“We challenge the government to provide convincing evidence to parents, school leaders and children that not being selected aged 11 will motivate any child to make better progress than before.”

The letter mirrors those submitted by groups of headteachers in many other parts of the country who oppose the government’s proposals.

Meanwhile, an education think tank has questioned the extent to which the government plans will help poorer brighter children.

It claims that applying the conditions under the government’s own terms for new grammars would benefit just six areas, not including Kent.

The Education Policy Institute modelled the impact of government plans by looking at how 32,844 districts would be affected.

The full list of Kent headteachers who have signed the letter is:

• Stephen Adamson, Executive Headteacher, St Gregory's Catholic School & Ursuline College;
• Stephen Carey, Headteacher, Saint George's C of E School; Kate Greig, Headteacher, King Ethelbert's School; Philip Karnavas, Executive Headteacher, Canterbury Academy;
• Nicki Mattin, Principal, Spires Academy;
• John McParland, Principal, The John Wallis Church of England Academy;
• Claire Owen, Principal, Herne Bay High School;
• Chris Russell, Executive Headteacher DOYMS & CEO Astor Academy;
• Tracey Savage, Headteacher, Sandwich Technology;
• School Matthew Tate, Headteacher, Hartsdown School;
• Brendan Wall, Headteacher, St Simon Stock Catholic School;
• Michael Walters, Headteacher, St Anselm's Catholic School;
• Jon Watson, Headteacher, Canterbury High School;
• Sam Williamson, Principal, Dover Christ Church Academy;
• Mike Wilson, Headteacher, St Edmund's Catholic School; Alan Brookes, Headteacher, Fulston Manor School and CEO of the Fulston Manor Academies Trust;
• Jane Hadlow, Headteacher, New Line Learning Academy; Wayne Barnett, Principal, Mascalls Academy;
• Sally Lees, Principal, Homewood School and Sixth Form Centre;
• Jason Feldwick, Principal, St Augustine Academy;
• Mike Cater, Headteacher, Wrotham School;
• Matthew Wright, Executive Headteacher, Wrotham and Aylesford Schools;
• Patrick Hannaway, Executive Headteacher, Holmesdale and Malling Federation
• Richard Billings, Headteacher, The Towers School and Sixth Form Centre;
• Anne Davis, Headteacher, Dartford Science and Technology College;
• Catrin Woodend, Headteacher, The Abbey School;
• Warren Smith, Principal, The Folkestone Academy;
• Steve Carey, Headteacher, Saint George's C of E Schoo;l Chris Norwood, Headteacher, Northfleet School for Girls; Harry Ingham, Thamesview School;
• Matt Barron, Headteacher, St John's Catholic Comprehensive;
• Natalie Willbourn, Headteacher, Orchards Academy.