The nude calendar helped shake up the view of the WI

Faced with weak sales and tired fashions when he took over in 2004, M&S chief executive Stuart Rose asked the WI to help vet its new clothes.

The WI agreed and more than 800 of its members became a focus group that gave their opinions on new lines.

"Their feedback has had a direct impact on our buying," said an M&S spokesman.

"They gave a thumbs up to the improved quality and fit of fabrics but said they wanted to see more fashionable items in the collection.

"They are really keen on being fashionable and that has helped us design new collections."

Recovered profits

M&S has been reaping the benefits ever since, and last month reported that its annual profits had jumped to �965.2m, not far from the record �1bn level it attained in 1998 before its decline.

A voluntary organisation, the WI has about 200,000 members across the UK.

Originally a rural group that helped to connect women and promote a sense of community, the WI said that today it was becoming increasingly popular in urban areas as many people sought out a network of friends and support.

In recent years, faced with a diminishing membership base, the WI decided to focus its attention on a younger audience.

At the same time, a few high profile incidents helped change the way the WI was perceived including a nude calendar of its members, and the slow hand clap endured by Prime Minister Tony Blair when he addressed one of its meetings.