Keira Knightley, Cara Delevingne, Carey Mulligan, Rebecca Ferguson, Naomie Harris and Emerald Fennell are among the female celebrities demanding a clampdown on bullying and sexual harassment in showbusiness. The group are only six of 25 high-profile names who submitted an open letter calling on creative bodies in Britain to help fund a new watchdog – the Creative Industry Independent Standards Authority (CIISA) – to probe complaints in the music, film, television and theatre industries. Their letter stated: “So many of us in this industry would have loved to have an objective outside body that…