You could not quite describe Terence Rattigan’s The Deep Blue Sea as a rallying cry for the sexual liberation of women trapped in joyless marriages. Yet even a production as limp as Edward Hall’s cannot disguise the fact that 56 years after its premiere this historic play still strikes notes of radical daring in our own age of supposed sexual equality. The liberal-hearted Rattigan sketches a portrait of grey, puritan England, strapped in the corsets of duty and decorum, implicitly arguing that it would become a better, happier place if it loosened its stays.

Ironically inspired by the suicide of one of Rattigan’s gay lovers, The Deep Blue Sea extends its compassion to Hester Collyer, the childless, middle-aged wife of a High Court judge, whom Greta Scacchi invests with a cut-glass accent but little emotional turbulence.

Lady Collyer, a vicar’s daughter, sacrifices her marriage, financial security and social position for a love-affair in a Notting Hill rooming house. The object of her obsessive passion is the far younger Freddie, Dugald Bruce-Lockhart’s powerfully characterised Battle of Britain pilot, who lacks a role in the post-war world and cannot rise often enough to the challenge of loving Hester, despite his sexiness. So by controversially abandoning the responsibilities of marriage, in pursuit of sexual pleasures that no proper English lady of the Fifties was supposed to need or enjoy, Rattigan’s heroine lays her heart and mind open to disappointment with Freddie.

The opening scene, when Hester is rescued from a gas and aspirin suicide bid, made because Freddie forgets her birthday, creates a novelettish impression. This may be because Hall’s production lacks the strong, period atmosphere Karel Reisz bought to his historic Almeida production with Penelope Wilton as Hester. Francis O’Connor’s tenement setting, which boasts one translucent wall, looks appropriately down-at-heel. Sadly Geoff Breton and Rebecca O’Mara caricature Hester’s lower middle class neighbours and act with their hands as if they were voluble Italians, while Jacqueline Tong’s landlady sounds all too winsome and golden-hearted.

It is thanks to the unravelling of Hester’s affair with Freddie and Sir William’s attempt to win her back that The Deep Blue Sea makes such a devastating impact. Rattigan’s Hester owes something to Tennessee Williams’s desperate, sexually voracious heroines. The handsome Scacchi, faintly redolent of Mrs Thatcher in her haughty prime, goes elegantly through the motions of emotion. Yet she is little wracked and rent asunder by love. Even her brief show of tears have a crocodile quality. Although supposed to be struggling in The Deep Blue Sea she remains cresting the shallows while Tim McMullan’s struck-off, gay and middle European doctor encourages her to struggle on. Simon Williams’s judge, the model of stoicism, desiccated reserve and reticence, serves as a perfect period piece. Bruce-Lockhart’s big achievement is to make the egotistical, emotionally retarded Freddie moving, beset with sadness over his inability to love Hester.

The Deep Blue Sea, though, depends on Lady Collyer’s serious sexual blues which here are coloured in too pale a shade of bright.