Some comprehensive schools are more “socially selective” than grammar schools, according to new research which has called on the government to review the admissions code in England to improve access for poorer pupils.

While grammars are inherently selective, as admission is based on passing an 11-plus examination, comprehensive secondary schools admit local children, regardless of academic ability or social background, based on a school’s admissions policy.

However, research by the Sutton Trust, a charity that specialises in social mobility through education, has identified more than 150 state-maintained comprehensives that it says are more socially selective than the average grammar school.