There is a lot more of Miss Cooper, the hotel manageress, too in the play, but Wendy Hiller managed to scoop Best Supporting Actress for her role in the film. Niven of course won the Best Actor, but it seems a blustering fake performance, but then he is playing a blustering fake. Kerr is marvellous as the downtrodden Sybil, who finally stands up to her bully of a mother - Gladys Cooper being very malevolent here, as she was to Bette Davis in NOW VOYAGER. Hayworth and Lancaster add the Hollywood gloss and are perfectly adequate. The film is one of 1958's big enduring ones, up there with I WANT TO LIVE!, THE DEFIANT ONES, THE BIG COUNTRY, THE VIKINGS, SOUTH PACIFIC, AUNTIE MAME etc.
I also saw Rattigan himself at the BFI giving an entertaining talk also in the early 70s. The 1958 film though, directed by Delbert Mann, is the version most people know and like, even though it does not do full justice to the play and Rattigan's plea for tolerance for those who are 'different'.