The UK’s social mobility tsar has cast doubt on Liz Truss’s plans to revive grammar schools in England, arguing that they mainly benefit children whose families can afford to coach them to pass entrance exams. Katharine Birbalsingh, the headteacher named last year by Truss as chair of the government’s social mobility commission, said selective schools educated few disadvantaged or working-class pupils because they struggled to win places. “The problem with grammar schools nowadays is that, because there’s such an industry around preparing children to get into grammar schools, if you don’t have the resources or wherewithal to prepare your child to get in, then you can be left out,” Birbalsingh said in an interview with LBC’s Nick Ferrari. “You look at grammar schools and think, how many children from deprived backgrounds are there, how many working-class children are there? There aren’t so many, these days. “It’s not wrong to suggest that in the [past] grammar schools would propel certain working-class children forward. I’m not sure they do that so much nowadays.” Kit Malthouse, the education secretary, said this week that Truss wanted to “address the strong desire in quite a lot of parents to reflect the benefits that many got from grammar schools, in the wider education system. And so we’re definitely going to be beavering away at that, and see where we get to.” Birbalsingh said she looked forward to hearing how Malthouse planned to address the selection problem, which she suggested “didn’t exist” in 1975. The creation of new grammar schools has been banned in England since 1998, but Truss is said to be keen to repeal the ban. Campaigners against selection say the tests favour those who have been privately tutored or who attend independent schools, leaving few places for children from poorer backgrounds. “The problem with exams is they never test raw ability. They are often testing the preparation for them, which is right and proper,” Birbalsingh said. “But if you haven’t had that kind of preparation then how are you meant to compete with those who have? That’s the problem with grammar schools.” Birbalsingh is the founder of the Michaela community school in Wembley, north-west London, known for its firm discipline and high academic standards – which has led her to be known “Britain’s strictest headteacher”.