When the ladies of the Rylstone and District Women’s Institute decided to bare all for a cheeky calendar, the idea was to raise a few hundred pounds to buy a sofa for their local hospital.

Photographed in the women’s kitchens and living-rooms, the Alternative WI Calendar was tasteful nudity, Jam and Jerusalem style, with the women posing nude as they arranged flowers, poured tea and painted watercolours.

Within its first week the calendar had sold out, and over the following year hundreds of thousands of copies were sold on both sides of the Atlantic. The WI ladies from the Dales near Skipton went on to raise more than £2 million for Leukaemia Research, and their story was made into a hit film starring Helen Mirren and Julie Walters.

Now the story of the world-famous WI has been adapted for the stage and is coming to Bradford next month. Calendar Girls, written by Tim Firth, who wrote the screenplay for the 2003 film, stars Lynda Bellingham, Patricia Hodge, Sian Phillips, Gaynor Faye, Brigit Forsythe, Julia Hills and Elaine C Smith.

“I always said I’d only take my clothes off if it was for the right role – and I can’t think of a better role than this,” smiles Gaynor, who plays Miss November.

“It’s such an inspiring story. It started as a simple concept and became something huge. It captured the public’s imagination, partly, I think, because these were just ordinary women who had an idea and made it happen. Despite what has happened to them since they’ve never lost sight of what inspired them to do it in the first place.

“I remember watching the film and thinking it was a moving story, but with a great sense of fun. That really comes across in the play too; you’re laughing then crying in a matter of minutes. We often turn to each other with our eyes filling up!

“There are moments of pure genius in the script – Tim Firth is a fantastic writer and has an amazing insight into what makes women tick.”

Gaynor says the cast made a point of not preparing too much for the nude scenes. “We all decided that since we were playing real women we needed to look like real women, not models,” she says. “The day we did the photoshoot we’d only just met so stripping off for the camera was a good ice-breaker! Lynda Bellingham, who plays Annie, just stood up and pulled off her robe – it was such a great thing to do because it immediately made the rest of us less nervous.

“The nude scenes are beautifully choreographed to make sure there are strategically placed items around us so we don’t show too much. Then again, this is live theatre where anything can happen!”

Gaynor, 36, says the play explores the relationships between all the women involved. “The film focussed mainly on Chris and Annie, (based on Tricia Stewart and Angela Baker), but here we find out more about the others too,” she says. “The play is an ensemble piece – just like the real-life story is – but the essence of the film is still there. It looks at why they joined the WI and why they each choose to pose naked. It was a massive decision for these women.

“My character, Celia, was played by Celia Imrie in the film but she wasn’t really explored. In the play you discover that she’s a bit different from the other WI members; she’s younger and part of the country upper crust set – she spends most of her time in designer shops.”

Gaynor has met the real Calendar Girls. “Being a Yorkshire girl, I’ve met them at various functions over the years. I’m full of admiration for them,” she says. “It’s quite a responsibility playing a character based on a real person, but then I feel responsibility with all my roles.

“It’s nice to play Celia because she’s different from the roles people usually associate me with. I tend to play mumsy characters, even though that’s not really me, but she’s far removed from that.

“I’d love to play an evil character but I rarely get cast in that kind of role.”

The Calendar Girls became a global phenomenon. The ladies of the Rylstone and District WI, nestling in the Skipton countryside, were suddenly stars on the red carpet. They were mobbed for autographs, they appeared on the Jay Leno chat show, watched by millions of Americans, and were thanked in person for their fundraising efforts by Prince Charles.

Now you can buy Calendar Girls preserves, chocolates, gardening tools, greetings cards and recipes. Part of the women’s appeal lay in the simplicity and charm of their original calendar; here were rural WI ladies bottling fruit, loading apples into a cider press and playing the piano, tastefully covered with a teapot here, a cake-stand there. “We’re going to need considerably bigger buns,”

came one memorable line from the film, referring to the ample charms of Miss November, posing topless behind a pile of iced buns. Each photograph featured a sunflower, the Calendar Girls symbol.

Sunflowers are close to the hearts of the Rylstone WI ladies, particularly Angela Baker, whose husband John had grown them before his death from non-Hodgkin’s lymphoma, aged 54, in 1998.

An assistant park officer for the Yorkshire Dales National Park, John grew sunflowers and gave them to friends and family in the hope that he’d live to see them flower.

John’s death stirred Angela and her fellow WI members to create their calendar. Initially the idea was to raise enough for a sofa for the visitors’ lounge in the hospital where John was treated.

The calendar photographs were taken by Terry Logan, a former professional photographer married to one of the members. Released in April, 1999, it was an instant hit. An additional 10,000 copies were printed, all of which were sold within three weeks.

A few months later the calendar had sold 88,000 copies and an American version was launched – selling more than 200,000 copies and outselling Britney Spears’s calendar. There have since been several new calendars, including a recipe version for 2008 featuring pictures of the ladies cooking.

Calendar Girls runs at the Alhambra next week, from Monday to Saturday. Tickets are available on (01274) 432000.