An edited version of this letter from Sir Peter Lampl was published in the Mail on Sunday.

You report (“Anger as poorer pupils with low 11-plus marks get grammar places”, p.23, 11 October) that critics have attacked moves by grammar schools to enable poorer students to gain places with lower marks as ‘social engineering’ that ‘discriminates against the middle classes’.

Far from criticising these grammar schools, we should be applauding them. Our research has shown that less than 3% of pupils at grammars are on free school meals, compared with 16% of the population, whereas nearly 13% come from private prep schools, which educate just 6% of youngsters.

That is the real unfairness in the system. Many well-off middle class parents pay prep school fees or private tutors, something not open to those on low incomes, and cheat the system in the process. By introducing a series of steps that give poorer pupils a more level playing field, these enlightened grammars are simply seeking to redress the balance