WEDDING FASHION:It's the most coveted job, and the best-kept secret in the notoriously gossipy fashion world. So who is designing Kate Middleton's dress? asks ROSEMARY MACCABE

SINCE THE MOMENT the engagement of Prince William and Kate Middleton became public, speculation has been rife as to the identity of the all-important wedding-dress designer. Lest we get carried away with the hype of it all, it’s worth bearing in mind that, although the run-up to this wedding might seem as if it has gone on for years, the couple announced their engagement a mere six months ago, and will marry next Friday in Westminster Abbey.

But while Diana Spencer announced the designer of her wedding dress – David Emanuel, a Welsh designer best known as, well, the designer of Princess Diana’s wedding dress – a month before her wedding in 1981, the house of Windsor has been infuriatingly tight-lipped with details of Middleton’s dress choice, and the closer we get to the day, the more rife the speculation has become.

Which is why we have compiled this handy guide to dressing the princess-in-waiting. We name the front runners, the near-misses and the outside bets – but bear in mind, it’s all to play for between now and Friday.

DREAM DESIGNER: Christopher Bailey

Bailey, for whatever reason, hasn’t been a strong contender for the design job, but his pedigree is assured. Creative director at Burberry since 2001, Bailey has been responsible for combining the label’s traditional British heritage with a fashion-forward aesthetic that has seen it move from Daniella Westbrook to must-have territory.

The iconic British label would be a perfect fit with Middleton’s classic look – plus, the future royal has been spotted out and about on more than one occasion wearing Bailey’s designs. Burberry, though not famed for its gowns, has a sort of posh-girl-goes-hunting vibe that would suit Middleton, and it would make an unexpected, exciting change for Bailey, were he charged with designing the dress. What could we expect from Bailey’s creation? Floor-length, flowing fabric and a touch of whimsy. We’re not holding out much hope of a Bailey-Windsor mash-up, but it’s good to have a dream.

ALSO RAN: Alice Temperley

Another name in the hat for the accolade of “designer to the Princess” is Alice Temperley, the British designer known for having her clothes seen on some of the world’s most famous women, including Claire Danes, Sienna Miller and – Kate Middleton.

In spring 2010, Temperley upped her cool credentials by launching Alice by Alice Temperley, a younger, hipper line, modelled initially by Daisy Lowe, daughter of Pearl Lowe and Gavin Rossdale. But Temperley is firmly in the middle ground – neither avant-garde enough to run the risk of being considered an outlandish choice, nor traditional enough to be a shoo-in. Still, this offends-no-one perspective may be just what Kate is looking for, and Temperley does do a lovely line in pleasant, if not exactly mind-blowing frocks.

Temperley’s cause gained credence last week when Middleton’s mother Carole was spotted at her atelier, along with her sister Pippa, bridesmaid and rumoured lady-in-waiting to the future princess. Could it be that sister and mother dearest were engaged in wedding-dress negotiations?

ODDS-ON CHOICE: Sarah Burton at Alexander McQueen

The strongest murmuring surrounding the dress hinges on Sarah Burton, creative director at Alexander McQueen. Rumour has it that Alexandra Shulman, editor of British Vogue, advised Middleton to look to Burton for her sartorial wedding needs, and that Middleton obliged.

Although the wearing of McQueen would surely be a great tribute to Alexander McQueen, who died in February of last year, the idea of Middleton moving in such a daring direction seems unlikely. The house of McQueen is famous for producing lavish and, above all, unconventional and rebellious collections, the most famous of which, in 1995, was entitled “Highland Rape”.

The most recent Alexander McQueen show, autumn/winter 2011, did, however, have a strong emphasis on “gowns”, many of which were white – and the flames of the rumour have been stoked by Vogue’s May 2011 wedding issue, which doesn’t include a single design by Burton, which many see as an indicator that the house of McQueen is closing ranks ahead of the royal unveiling.

FROM THE LEFT FIELD: Sophie Cranston

The most surprising name mentioned in the run-up to the wedding has to be that of Sophie Cranston, designer at the little-known label Libélula. The announcement was made by Yvonne Yorke, Huffington Post royal correspondent, who stated that she had “heard who was designing Catherine’s wedding dress four months ago but kept it a secret in accordance with palace wishes”.

Cranston’s label Libélula, which means “dragonfly” in Spanish, was set up in 2002 during a sojourn in Spain. The Libélula website states that it is a label “known for its in-house-designed, vibrant prints and beautifully cut, timeless and flattering shapes . . . with an innate sense of colour and use of luxurious fabrics”. It has also recently branched out into a collection of bridal and bridesmaid gowns.

The idea of Middleton championing a little-known designer in the creation of her wedding dress is not a far-fetched one. Nor is this label unknown to the bride-to-be – in January of this year, Middleton wore a Libélula coat to a friend’s wedding in Yorkshire, so it is definitely on her fashion radar.

NEW ADDITION: Jasper Conran

A more recent name in the mix is Jasper Conran, the British designer famed for traditional, classic cuts and simple shapes. On paper, he may be the perfect fit for Middleton’s Sloaney lady-about-town image. He is also responsible for designing Lady Sarah Chatto’s wedding dress in 1994 (below), as well as, slightly more offbeat, those of Jasmine Guinness and Paula Yates. Conran launched his made-to-measure bridal line in 2007, but is best known for his J for Jasper Conran collaboration with high-street retailer Debenhams and for his Tripp luggage collection, both indicators that cause some to doubt his credentials for the dress commission.

That said, stranger things have happened – and if Conran were to be employed in the creation of Middleton’s wedding dress, it would mean that a huge portion of the population would be in a position to pull out their own Jasper Conran items and wave them at the television ecstatically, chanting,

“One of us, one of us!”