‘You know what your father thinks about all this acting,” says harried housewife Jill to her son, Sam, who is hopeful of a role in his school play, A Midsummer Night’s Dream.

Sam knows only too well. To his dad, Mal — about as far from the New Man as it is possible to be – acting is an activity exclusively for the limp-wristed. And Shakespeare is especially suspect — merely an excuse for men (so-called men!) to prance about in tights.

Mal’s attitude is of a piece with his whole outlook on life: his days revolve around drinks with the lads after work and lunchtime nookie with his bit on the side. Football is the only culture that concerns him. That his job is as a furniture store manager means that scenes at home and scenes at work can take place on the same set (a super job by Michael Holt) — another bright idea from the fecund mind of Alan Ayckbourn in this, his 70th play, first seen in Scarborough four years ago.

But this is not the brightest idea here. In a move that suggests that the introduction of Shakespeare into the script was far from accidental, he takes gender-swapping to lengths even the Bard did not attempt. “God help us”, Jill and Mal chorus in contemplation of their doomed marriage, as their bedside lights are dimmed. Help them He does in His own mysterious way: they wake up on the morrow to find each in possession of the other’s body.

The transformation is followed immediately by the interval at the Mill. During the break, I confess I was thinking that the cast were going to have their work cut out wresting much laughter from the changed situation. How wrong I was!

Thanks to superb performances by Karen Ascoe and Oxford-based Richard Stacey, and the comic conceits contrived by the playwright, we are offered an hour of utter hilarity. I can’t recall laughing so much in a theatre for years.

Deciding they must try to preserve appearances, the new-look Jill heads off for work at the furniture store – but not before ‘she’ has astonished schoolboy Sam (a well-drawn tangled-up teenager from Dominic Hecht) with the remarkable new interest his ‘dad’ is taking in his activities and welfare. Crikey, he even prepares breakfast!

The new ‘Mal’ shows the same touchy-feely approach at work, bringing consideration and diplomacy where once there had been only bullying and bluster, this time to the amazement of his son-in-law, the mega-macho Dean (Neil Andrew). Results follow, of course, as any management consultant would tell you.

Back at home, meanwhile, the real Mal is starting to absorb lessons about the woman’s lot. This involves not only how to put on make-up and select clothes (the mismatched outfits designed by Jane Kidd are a hoot), but also how to lend a listening ear. The confidences of daughter Chrissie (Katie Foster-Barnes) soon open his eyes to the true nature of her marriage to the violent Dean.

In all this we see the warm humanity that is a trademark of so much of Sir Alan’s work. Here it is presented in a manner that could hardly be bettered under director Terence Booth, whose pedigree as an Ayckbournian, with a long list of starring roles in Stephen Joseph Theatre premieres, could scarcely be improved upon.

Until July 10. Box office: 0118 969 8000 (www.millatsonning.com).