Can't afford couture but can't stand cut-price copies? Jigsaw has all the missing piece

In the beginning (well, the 1990s), there were designers. Feverishly creating in their lofty ateliers, they set the trends that filtered down to the high street and determined what the rest of us wore day to day. In the past few years, this process reached a terminal velocity, as big brands chewed up catwalk trends and spat them out as identical bargain buys in weeks, with results of dubious quality.

Now, as piles of unworn, shoddy designer imitations languish at the bottom of British wardrobes, our love affair with fast-fashion seems over. Women's glossies are packed with buzzwords such as "quality" and "craftsmanship", urging us to "invest" in well-made classics that will go the distance in these credit-crunched times. All well and good for those whose bank balances are robust enough to contend with designer price tags, but what is the alternative for everyone else? The answer could lie in a new wave of middle-market labels, with fashion's latest breed of star, the "creative director", at their helms.

Among them, working her magic on the womenswear brand Jigsaw, is Louise Trotter. Now in her third season at the company, Trotter has steadily transformed Jigsaw from the rather mumsy, irrelevant label it had become back into the high-street trailblazer it was when founded in the 1970s.

Though less high-profile than Jane Shepherdson, the woman credited with turning Topshop into a mass-market phenomenon and more recently responsible for giving fellow mid-market player Whistles a high-end makeover, Trotter has created a similar stir within fashion circles. At last month's London Fashion Week, the eagle-eyed would have spotted many a recent Jigsaw offering on the backs of the British style press.

If it has lacked the fanfare of the Whistles revamp, that has been a deliberate part of Trotter's strategy. "We never intended this to be an 'out with the old, in with the new' relaunch," explains the 35-year-old, whose career has included stints at Gap and Calvin Klein. "It was a modern interpretation of Jigsaw, reinventing shapes, fabrics and colours. It's about making it more inclusive, not turning it into something exclusive."

Her first two collections were a testament to this philosophy, channelling a designer aesthetic while maintaining an accessibility in price and wearability – crucial to a high-street brand. Her approach has focused on reworking the brand's bohemian British style with a contemporary edge; silhouettes are more structured, shapes are cleaner and subtle detailing adds a luxurious finish.

The autumn collection, hitting stores now, is packed with covetable pieces. Inspired by Tippi Hedren's character in Alfred Hitchcock's The Birds, the range mixes ladylike pencil skirts and slim, tailored trousers with soft feminine blouses and knitwear. Fabrics and prints have a luxurious vintage quality, while accessories such as patchwork bags come in soft, slouchy leather. "Jigsaw has always had this slightly dishevelled, very British quality, which I've kept, but there's more structure there now," explains the Sunderland-born Trotter.

In keeping with the new aesthetic of the clothes, Jigsaw's latest ad campaign, out this week (and previewed exclusively here, right), marks a return to the sophisticated promotional images Jigsaw created in the 1990s by hot names such as Juergen Teller and Terry Richardson. This time, Trotter has collaborated with the acclaimed photographer Iain McKell on an Alice in Wonderland-style shoot that would not look out of place in the pages of a style magazine. Like the collection itself, the imagery is richly beautiful while maintaining an endearing British quirkiness.

What makes Trotter's work particularly interesting, however, is the new direction it represents in terms of mainstream fashion as a whole. No longer must consumers choose between the extremes of the exorbitant designer original and the cut-price version. Instead, creative directors such as Trotter are bringing a designer's artistic integrity to big brands capable of realising those ideas on a large enough scale to make them affordable. ("The budget I have for sourcing fabrics at Jigsaw is probably bigger than when I worked for Calvin Klein," she confides.)

Rather than slavishly copy the high-end designers, these mid-market players are able to tap into high-end trends and adapt them for a broader market, producing clothes that are stylish and contemporary but with a lifespan greater than a single season. It's a change that Trotter feels was long overdue.

"When I joined Jigsaw two years ago, the middle of the British market was really lacking. I was working in New York and I used to come back and feel really sad about how the high street had totally lost its way. It had become very polarised; it was either Topshop and Primark, or it was luxury brands. Part of the reason I came back was I wanted to do something accessible that wasn't luxury, but wasn't a 'copy-fashion' brand either. What's happening now is really quite exciting."

It seems the buying public agree. Bucking the standard theory that times of economic woe spell austere fashions in drab colours, Trotter says that it is Jigsaw's luxurious cashmere sweaters and jewel-coloured dresses that have been flying off the shelves: "There's a real trend towards optimism in the way British women are dressing." If Jigsaw's example is the shape of things to come on the high street, they have good reason.

www.jigsaw-online.com