Based on a true story, Calendar Girls is a quintessentially British comedy that has all the makings of another Full Monty, Billy Elliot or Bend It Like Beckham.

The film's blend of earthy humour and tragedy, with an underlying message about the enduring power of love and friendship, is utterly irresistible.

And the glorious vision of some of this country's most beloved actresses in their birthday suits (their modesty preserved by strategically positioned fruit, Belgian buns and a watering can) certainly won't hurt box office takings.

Nigel Cole's magical feature is inspired by the real-life escapades of the Rylstone and District Women's Institute, who became overnight celebrities when they posed naked for an alternative calendar to raise funds for leukaemia research.

Mirren and Walters lead the brilliant ensemble cast as best friends Chris and Annie, who hit upon the novel fund-raising idea when Annie's husband John (John Alderton) dies from the disease.

The other members of Knapely WI, nestled in the heaving bosom of the Yorkshire Dales, are initially opposed to Chris's hare-brained scheme.

Who in their right mind is going to spend good money on a calendar of pictures of middle-aged women au naturelle, flab and stretch marks and all?

However, Chris and Annie's enthusiasm is contagious and soon ten other women including bohemian Celia (Imrie), dowdy housewife Ruth (Wilton) and plucky Jessie (Crosbie) are throwing caution and their aprons to the wind to pose for local photographer Lawrence (Philip Glenister), despite the disapproval of regional WI chairwoman Marie (Geraldine James).

The calendar is a roaring success and inevitably, the media gets hold of the story.

Chris, Annie and co are propelled into the spotlight and are whisked away on a whistle-stop publicity tour of Hollywood, which tests Chris and Annie's friendship to the limit.

Calendar Girls more than lives up to the deafening hype.

Juliette Towhidi and Tim Firth's screenplay is beautifully observed, punctuated with plenty of laughs and the odd tear.

The ensemble cast, led with gusto by Mirren and Walters, bring warmth and energy to their roles and make us care deeply about these plucky heroines and their daring scheme.

At its heart, Calendar Girls is a life-affirming tale of everyday folk accomplishing extraordinary feats.

One viewing won't be enough - you'll definitely want to see it again.

Starring: Helen Mirren, Julie Walters, Celia Imrie, Annette Crosbie, Penelope Wilton

Director: Nigel Cole

Certificate: 12A

Running time: 108 mins