The ancient cult of Diana flourished around Lake Nemi, near Rome, where women hoping to conceive offered terracotta figurines to the goddess of fertility and hunting.

Future historians will be no less intrigued by the latest evidence of the modern cult of Diana, Princess of Wales.

From today, anyone with £1,000 to hand and a serious enthusiasm for Diana memorabilia can purchase a contemporary relic: a fragment of the silk used for the princess’s wedding dress.

David and Elizabeth Emanuel, the British designers who created the dress for the eleborate ceremony at St Paul’s Cathedral on July 29, 1981, promise that this will bring the buyer “a step closer to the woman who is still alive to so many throughout the world”.

The fabric has been cut into 1,000 swatches of roughly four square inches, to go with every copy of A Dress for Diana, a lavish coffee-table account of the Emanuels’ best-known assignment. If all 1,000 sell, the venture could realise £1 million.

Publicity material for the sale claims: “We are able to step back in time, join that shy young girl as she made her hesitant way down the aisle in front of millions of people watching, as she took step after dainty step to meet her future, as dramatic and tumultuous as that proved to be.”

It will soon be impossible to avoid reminders in bookshops, newspapers and on television that Diana died ten years ago this August.

However, Elizabeth Emanuel, who separated from her husband in 1990, denied that they were exploiting the Princess’s memory. “It’s not a bit of her. It’s a bit of the day and the whole experience of that time,” she said yesterday.

The offcuts from the dress and the remnants of the bolt of silk that was used to make it have been kept in a bank vault for most of the 26 years that have passed since the Royal Wedding.

Ms Emanuel, 53, who has survived a well-publicised bankruptcy to rebuild her career, said that they had intended to publish the book last year, on the 25th anniversary of the wedding, but missed their deadlines.

“The dress has become iconic on its own. There’s a lot of books about Diana but this is a book about something that we did. I think it’s the right time to tell our story.”

The Emanuels were in their twenties and fresh out of art college when the young Diana Spencer invited them to design her wedding dress.

Work on the dress, and its record-breaking 25-yard train, was conducted in utmost secrecy, Ms Emanuel said. “We had to keep everything in-house because we were so scared of details getting out. We got my mum in to sew sequins.

“We had paparazzi renting rooms across the street and going through our rubbish bins, so we put up blinds and hired Jim and Burt, two security guards.”

The Princess, who made around ten visits to their West London studio, was referred to by the codename “Debra”. Buckingham Palace, where they went for final fittings, was “BP”.

“We charged 1,000 guineas for the dress and the bridesmaids’ costumes, but Dave and I would have given it away.”

Other Diana-related products being launched this summer include 12.23, an upmarket conspiracy thriller by the Booker Prize longlisted author Eoin McNamee; The Accident Man, the debut of “a well-known investigative journalist” writing under a pseudonym; and The Diana Chronicles by Tina Brown, former editor of Vanity Fair. Production has started on a television drama focusing on the princess’s last days. ITV and Channel 4 plan documentaries examining the relationship between Diana and the paparazzi and the BBC is planning a commemorative edition of Songs of Praise.