Justin Welby, the Archbishop of Canterbury, has launched an outspoken attack on the grammar school system in Kent.
He told an audience at Canterbury Christ Church University that attending grammar schools deprives children of “diversity” in their education.
But his comments drew criticism from advocates of selective education who argue that it provides children from poorer backgrounds the opportunity to improve their life chances.
Mr Welby gave a talk and question and answer session at the university’s Augustine House on Wednesday to promote his new book Reimagining Britain, which explores the moral and sociological changes the nation has undergone since 1945.
He said: “I remain – and I know in Kent this is very controversial – I remain cautious, more than cautious, about selection.
“I have absolutely no doubt that the right children going to grammar schools benefit hugely, but what they don’t have is diversity.”
Mr Welby, who attended Eton College between 1969 and 1974, said he had later been the governor of a comprehensive school and witnessed children from all backgrounds mixing together.
He added: “One of the key things for education is to teach us to live in community. To value the other, regardless of their capacity.
“The tragedy of the future is if only the brightest and the best are considered to be the most important.”
Kent is one of the few counties in England to retain grammar schools and in the Simon Langton Boys School Canterbury is home to one of the highest achieving in the whole country.
Grammar school advocate Chris McGovern of the Campaign for Real Education accused Mr Welby of being “out of touch with the modern world”.
“He seems to have a mental blockage with regard to selection,” Mr McGovern said.
“Overwhelmingly, the main form of pupil selection for our schools is by house price. Most better-off families send their children to comprehensive schools in better-off areas where they can afford to buy a house. This leads to social segregation of schools that is based on income.
“After 50 years of comprehensive schooling we are left with the worst social mobility rate in developed world.
“The archbishop is supporting a school system that supports that richest and the most privileged.”
Kathy Gyngell, co-editor of the Conservative Woman website, added: “‘He is denying opportunity to children and choice to parents, and he is also denying educators the right to choose which children they should teach and how they should do it.”