How much do grammar schools change grades?

England is to get its first "new" grammar school for five decades after it was agreed an existing school could build an "annexe" several miles away.

Weald of Kent school in Tonbridge will open a girls' annexe in Sevenoaks, Kent, with 450 places, allocated by academic selection - getting round a ban on opening new grammar schools.

Debate rages over the pros and cons of grammar schools.

Rebecca Allen, director of Education Datalab - a research organisation concentrating on education - went through the statistics on the Today programme, arguing that there are more losers than winners in the grammar school system.