Because it’s stylish comedy or social drama? “The two are indistinguishable, ” says Murray. “Wilde said his epigrams were subversive and meant to go off like a bomb. Lord Darlington uses wit as a mask to let him say things people would otherwise find offensive, while the Duchess of Berwick is a sad, damaged, disillusioned lady. Wit is her way of coping and hitting back at society. ”

In this way the characters are like Wilde, who coaxed a new society audience into the theatre and then launched a devastating attack on them, made palatable by his wit. Though deep down, Murray believes, they took offence, which helps to explain the vitriolic reaction after Wilde’s trials.

In the play, Mrs Erlynne is the woman with a past whose experience has implications for the stability of society, especially the reputation of the virtuous Lady Windermere. Goodness is put in doubt when this lady’s fan is found in Lord Darlington’s rooms and there are many plot convolutions before the truth is revealed.

The only characters not to display Wildean wit are the Windermeres (one epigram between them) because they do not compete in this society. Yet the play is Lady Windermere’s moral journey. “At first she is pure but untried. She sees good and bad as absolutes. By the end she realises life is more complex and tries to tell Lord Windermere so. Though with the right actress the audience can - as they must - sympathise with her.”

At Ipswich, Lord Darlington had seemed less the confident man about town than usual. Murray goes along with this. “He is sulphurous - very lonely, very unhappy. He endlessly says he loathes society. He has never had a satisfactory relationship with a woman.” The male group forces itself on him in his rooms and he breaks into, rather than joins in, their banter, earnestly telling them he genuinely feels for Lady Windermere.

Murray is convinced there is a mutual attraction between them and in rehearsals the unanswerable question has been endlessly discussed - which man, her reliable, loving husband, or the dangerous, exciting Darlington, would be better for Lady Windermere?

These various qualities reflect Wilde’s personality, which he poured into the characters. The moral Christian Wilde is seen in Lady Windermere, and the guilty Dionysiac in Lord Darlington. Wilde used his wife as a cover for illicit affairs, as Lady Windermere accuses Mrs Erlynne of doing, while Wilde, as Lady Windermere nearly does, left his children.

Like Cecil Graham, Wilde enjoyed pinning people like butterflies with his wit and watching them wriggle. And Wilde’s relationship with Lord Alfred Douglas is reflected in that between the elegant Dumby and Cecil Graham, the outsider with a brilliant intelligence.

“Wilde never wrote a word that was not serious and this play shares with The Importance of Being Earnest the themes of the orphan and the desire for a union obstructed by society,” Murray says. In The Importance of Being Earnest, the characters never speak what they feel; in Lady Windermere’s Fan they often do.

The witty passages are restricted - none at all in act four. The third act uses wit seriously, placing the men’s clubbable joviality straight after the two women’s very strong moral discussion, while the final act’s farewell, in which Lady Windermere opens up to Mrs Erlynne as if she has found a mother for the first time, ironically without realising she has found her mother, is deeply moving.

Murray points out how much Wilde admired Ibsen. “Rehearsing the play you know why he did so. You can see the influence in the depth, subtleties and realism of emotion. These are present throughout the play,” he says. Even a minor character such as Lady Agatha “can’t bear her mother. She finds a way to cope but is rebellious; a human being not just a mouth who’s being crushed.”

Lady Windermere’s Fan is at Manchester Royal Exchange Theatre, Upper Campfield Market, from December 5 to February 1. Tickets: 0161 833 9833