It was revealing that, in the course of researching this feature to determine which of the high street stores currently offer size 18 and over, the sizes most frequently sold out on the stores' websites - and we are talking brand new spring merchandise here - were the 18s, 20s and 22s.

Which demonstrates two things: one we already knew (though British retailers are in denial), that the average UK woman is not the borderline-anorexic size 6 seen in magazines and on the catwalks, but a somewhat curvier 18 or 20; and two: that curvier women are positively eager to splash their cash when they find gorgeous clothes that are made to fit them.

Actually, the earlier observation that "British retailers are in denial" is a tad unfair and no longer strictly accurate. The British high street has largely wised up to the fact that there is a whole demographic of curvy women who want clothes to fit them. It's just that, in general, while stores like Wallis, Dorothy Perkins, River Island, Next, New Look, M&S and Hobbs all offer sizes 18 in their mainstream collections - and some of them 20 and 22 - they do so with very little fanfare.

Whether this is for fear of putting themselves too squarely in the company of bigger girls, who, ludicrously, are still - despite the best efforts of gorgeous plus-size models like Crystal Renn and America's Next Top Model winner Whitney Thompson - not perceived as being as glamorous as the borderline anorexics, or whether these retailers are simply delinquent at marketing their more generous sizes, I really can't say.

But this failure among mainstream retailers to market their bigger sizes is odd, because all the evidence points to the fact that curvy women don't want to be forced into "specialist" retailers. They want to be able to buy in the same shops as those who are a size 8, 10 or 12. And in these difficult trading times, you might think that, if M&S offers most of its Autograph Collection up to size 22, and Debenhams offers much of its Designers At... collections up to size 20, they would be shouting about it.

At Debenhams, the best buys up to size 20 or 22 currently include a black leather biker jacket from Julien McDonald's Star Collection (now £137.50,), a one-shoulder diagonally pleated body-con black dress by Pierce II Fionda (£130) and a ladylike navy collarless mac by Ben de Lisi for Principles at £65.

At M&S, some of the best pieces available up to size 22 include a well-cut, Audrey Hepburn-esque, slash neck dress at £39.50, a hippy chic collarless lace-print blouse (£35), a horizontal stripe scoop neck dress at £39.50 and a flattering vertically panelled, semi-fitted dress at £59. M&S also has a plus-size shop for sizes 26 and 28. Next is another major high street name which offers much of its collection up to size 22, as well as a plus-size shop up to size 26. Some of the most alluring pieces from the mainstream collection include a tunic dress in a very on-trend abstract print (£18), a sleek blazer in cobalt, again a hot colour for spring, (£49), a pretty shift dress in red and cream with a waterfall frill (£45), and a brilliant, bracelet-sleeve jumpsuit from their Geri Halliwell range at £75 - all up to size 22.

Also on the high street, River Island goes to size 18; Wallis and Dorothy Perkins sizes 20 and 22; and M&Co offers most of its collection up to 22. New Look's Inspire range offers sizes 18 to 26 and H&M, which last year launched its Inclusive Collection, has now replaced it with H&M+, offering "modern essentials" in UK sizes 18-28. These currently include long sweaters and tops to wear with skinny jeans, a sharp blazer, white shirt and ankle-skimming trousers.

A little higher up the market, Banana Republic offers selected items up to size 18 and XL (18-20), and Hobbs sizing goes up to a nominal 18, but with measurements of 43" bust, 36" waist, and 46" lower hip, is equal to a very generous 20.

Fenwick's Bond Street has the collections of Ischiko and Annette Gortz, both of which go to size 20, while the Brent Cross branch offers Gerry Weber, Betty Barclay, Viyella and Joseph Ribkoff, which all go to size 20 and beyond.

Other mainstream brands which offer size 20 include Kaliko and Planet, while Alexon and Boden go to size 22 and Jacques Vert does size 24 in its frankly mumsy occasion ranges.

Among the specialists, Long Tall Sally's XL fits sizes 22 and 24, while Evans offers sizes 14 to 32, with some strong styling in a collection that still needs work. Websites with on-trend pieces for curvy girls include Yoursclothing.com, SimplyBe.co.uk, and ASOS Curve, while local plus-size specialists include Elaine in Redbridge, and Box 2 in King's Langley, which both offer a slew of strong UK and international brands.

The newly-opened Mitch, in England's Lane Belsize Park, is offering sizes 16 to 28, from brands which include Michele Jeans, Lucia, Evelin Brandt, Q'neel, Hanro and Spanx for shapewear and tights and Zandra Rhodes' clothing and jewellery, some of it exclusive to the shop.