In case you’ve been on another planet for the last decade, Calendar Girls is based on the true story of a Yorkshire WI group who bared all (albeit with the vital bits tastefully hidden), and produced a charity calendar.

This thoroughly heart-warming story has resulted in the original WI ladies raising over £2m so far, and the stage show — at the New Theatre this week — recently knocking Nigel Havers’s Rebecca off top spot to claim the record as the most successful play ever to tour the United Kingdom.

“No front bottoms!” declares Jessie (June Watson). “They’re reserved for just one man in my life — no, luv, he wasn’t my husband.” Chris (Lynda Bellingham) is busy organising the calendar photoshoot, and persuading other WI members to strip. Jessie is duly reassured to see the ample supply of iced cup cakes, which are on hand to cover her modesty. Cora (Michelle Collins), roly-poly Ruth (an especially warm performance from Debbie Chazen), Celia (Kathryn Rooney) and Annie (Jan Harvey) all fall into line — it’s the death of Annie’s husband from leukaemia that has inspired the calendar. Only branch chair Marie (Ruth Madoc) initially stands on her dignity. Wet behind the ears photographer Liam (Michael Peluso) is summoned — at first he scuttles out of the room immediately anyone removes as much as a cardigan, but gradually he becomes braver.

Of course there is opposition, particularly from a horrified WI hierarchy. But less is made of this in Tim Firth’s stage play than in his 2003 film. Here dramatic focus is provided by Jan Harvey’s emotional portrayal of the bereaved Annie as a woman shattered by her loss. But don’t let’s give the impression this is Chekhov, Calendar Girls is basically a thoroughly entertaining romp, which the entire cast belts out (judicious amplification might help their voices) with infectious enthusiasm. The hilariously staged calendar photoshoot is truly unforgettable.