The stakes were raised last year by former chief inspector Chris Woodhead when he unveiled his new chain of “back to basics” private schools. His Cognita group, backed by a pound;500 million private equity fund, bought 17 schools from Asquith Court, the nursery care provider, following its earlier purchase of Quinton House school in Northamptonshire. Other players in the increasingly competitive private sector include the Girls’ Day School Trust, which has 25 private schools in the UK, employing 3,500 staff, making it the largest single owner. Unlike Gems and Cognita, the trust is a non-profit making organisation.

The Christian United Church Schools Trust has 11 schools and, like Gems, has invested in the Government’s academies, sponsoring three of the independent state schools.