This is a very important and hugely entertaining play. In 1965, author Frank Marcus, the first drama critic on the Sunday Telegraph, prophesied mass hysteria over killed-off soap stars, the dangerous melding of fiction and reality in public entertainment and sexual skulduggery behind closed doors at the BBC.

The latter element involves a lesbian tug-of-love over the dimwitted 34 year-old female domestic partner, Alice, or “Childie” (Elizabeth Cadwallader), of butch alcoholic June Buckridge (a crop-haired, bracingly stern Meera Syal) with the BBC producer, Mrs Mercy Croft (Belinda Lang); Mercy has come to tell June that her character, a district nurse in a popular radio serial of everyday country life, is to be killed off.

I haven’t seen the play since the first production starring Beryl Reid, Eileen Atkins (Susannah York played Childie in the subsequent, disappointing film) and the imperious Lally Bowers; it remains just as funny and moving, and a fascinating “period” hybrid of both Pinter and Joe Orton, whose somewhat similar Entertaining Mr Sloane had opened in the previous year.

Belinda Lang is very Lally Bowers, and very good indeed, as the BBC viper, but Iqbal Khan’s production misses the beat of the play in making June quite so butch; there’s far more voluptuousness and tragic slyness in the role, or of course there was with Beryl Reid. And Cadwallader’s Childie is too one-note a screecher, inconceivably employed in a solicitor’s office, as she is.

There’s an element of grim hysteria about the show that is not relieved when Helen Lederer’s comedy turn of a downstairs Madam Arcati calls by, all flap and glare and fusspot inanity.

There’s gentleness and sadness in this play too, not least when we learn more about Childie’s past, or the bleakness of June’s future; how can she possibly accept the offer of a cow on “Toddler Times”?

Syal gives an outstanding performance, even if it’s the wrong one. And Ciaran Bagnall’s design of a large old-fashioned wooden wireless dominating June’s Devonshire Street flat (a stone’s throw from BBC headquarters) is ingenious even if it’s over-symbolic.

In all, though, following Charles Morgan’s The River Line at the Jermyn Street Theatre, this proves the second brave hurrah for a classic three-act play within a week.