The singer's glamorous gowns are a key part of her shows

A collection of 50 diva-style stage dresses - one to mark each year the Cardiff-born star has worked in showbusiness - will be auctioned for charity by Christie's on 18 September.

The 66-year-old singer from Tiger Bay is selling her unique collection to raise money for the Dame Shirley Bassey Scholarship at the Royal Welsh College of Music and Drama in Cardiff and the Noah's Ark Children's Hospital Appeal.

"I feel proud knowing I wore these gowns," she said. "I love them all."

All the dresses being auctioned at Christie's are the work of Ms Bassey's favourite designer, Douglas Darnell.

She has admitted that saying goodbye to the show-stopping outfits which have become her trademark will be quite a wrench.

"Parting with these beautiful gowns will be an emotional experience as they have brought me great success in my career and have been loved and admired by so many," she said.

Bassey pictured in another striking dress in 1974

The earliest piece up for sale is a 1955 sleeveless stage gown, known affectionately by Bassey as "the diamond dress", which is encrusted with thousands of Swarovski aurora borealis crystals and weighs at an incredible 13lb (6kg).

One of her particular favourites, a black velvet gown with a three-dimensional orchid made from crystals, will also be auctioned, as will the gold and silver sequinned and beaded gown associated with her first hit, the 1964 James Bond theme tune Goldfinger.

Another highlight will be a fabulous cat suit of natural coloured chiffon lavishly embellished with Swarovski aqua marine topaz and aurora borealis crystals - complete with matching coat - which Dame Shirley wore during her 60th Birthday Concert at Althorp Park in 1997.

The entire collection is expected to fetch more than �50,000 charity.

One company which has benefitted from Ms Bassey's love of glitz and glamour over the years is the Austrian crystal group Swarovski, whose gems have been used in many of her outfits.

"It is a wonderful opportunity to be working together with Christie's and Dame Shirley on such a noble event in order to raise money," said company vice-president Nadja Swarovski.

Wealthy fans are bound to bid for the dresses

Christie's deputy chairman Jussi Pylkkanen, added : "It is a tremendous tribute to Dame Shirley that, after 50 years at the pinnacle of the music industry she has taken a momentous decision to sell her famous dress collection.

"The exhibition, like the auction, promises to be a dazzling event and we look forward to raising a significant sum for the charities concerned."