IT used to be full of teenage girls spending their weekend pin money on skimpy T-shirts. But what was once famously a tat-shop is now a trendsetter and looking to take the next step in becoming a global brand: TopShop owner Philip Green has just announced his plan to open a $50 million flagship branch in New York next spring.
Its European high-street fashion rivals, Zara and H&M, already boast sizeable outposts in Manhattan, and Green - guided by TopShop's acclaimed brand director Jane Shepherdson - wants a slice of the action in America's most fashion-forward city. But how do you sell low-price, fast-turnover fashion to a city full of women who are wedded to the prestige of designer labels such as Donna Karan, Prada and Marc Jacobs?
The truth is, top American actresses and models make a beeline for TopShop whenever they are in London, with Sarah Jessica Parker and Sofia Coppola among the high-profile customers spotted in its stores, devouring the affordable jeans, tops and bags which mirror the best in international catwalk trends - and where America's most glamorous celebs go, the fashion faithful invariably follow.
Other British brands have succeeded in the US, but they have tended towards the luxurious: Stella McCartney and Nicole Farhi have shops in New York's Meatpacking district, while the likes of Aquascutum, Burberry and Hunter wellies are bywords for well-heeled elegance. The members-only hotel Soho House, created by Kirsty Young's husband Nick Jones, has become a home-from-home for stylish Brits - a focal point for artistic and media ex-pats that evokes scenes from Tom Wolfe's 'Bonfire of the Vanities'.
So what are the chances of survival for the cheap-and-cheerful UK chain in a market where the designer label is king?
"They have already established their fashion credentials," says Scottish fashion writer John Davidson. "They work with so many high-profile designers to turn catwalk style into mainstream clothing that it isn't really the high street store we used to see it as.
"TopShop has been a pace-setter for some time now, not a pack-follower. They are ahead of the game, so that's a good starting point."
Jane Shepherdson admits to "some nervousness" about the prospect of taking on Madison Avenue's finest. "Obviously we need to get it right: find the right [spot], choose the right store," she says. "We need somewhere that can give us real presence, like our Oxford Circus store in London, which is one of the best trading locations in the world.
"It won't happen overnight, because we need to get the location right before anything else. So many other businesses have gone to the US and failed miserably."
Reports suggest Green has already found a space somewhere between 60,000 and 90,000 square feet - though he is so far refusing to elaborate further.
"If we enter the United States, we're not going to be low key," Green told Womenswear Daily (WWD). "Every retailer's dream is to build a global brand. Look at what Zara and H&M have done. That's exciting."
"Can we do in the US what we do in the UK, which is deliver fresh merchandise three times a day at peak periods? We want to execute at the same level [in New York] as we do [in Britain]. We will pay the $20, $30, $40 or $50 million needed, but we don't want to fail. We are not a public company. We can afford to take a longer view to get it right."
TopShop currently boasts some 290 British stores, as well as 165 branches of TopMan, and is also poised for further expansion into Europe, with talk of store in Paris.
It has already dipped its toes into the New York market with a concession inside the Howard Street boutique Opening Ceremony, featuring lines designed by the likes of Jonathan Saunders, Preen and Markus Lupfer.
"We've sold loads of Baxter skinny jeans, and lots of shoes," says Shepherdson.
The decision to take TopShop across the Atlantic may have been inspired by the fact that it has joined the ranks of Harrods, Harvey Nichols, Selfridges, Liberty and Jenners as a 'destination shop' for American tourists in Britain. A Los Angeles traveller, posting on internet bulletin board TripAdvisor, writes: "I found myself thinking I needed to return just for one last fix, rather than visit the Tower of London or Stonehenge. The prices are great - 30 for unusual shoes, 15 for handbags similar to Marc Jacobs. The stock was very trendy for the 16-39 set. "
But isn't it all down to the allure of the exotic? When Scarlett Johansson told a British magazine that she visited Superdrug whenever possible while in London, wasn't she simply mirroring the awestruck British tourists who wander the aisles of US high-street pharmacies such as Walgreens and Duane Reed in search of ultra-cheap toiletries? They are no more exotic to Americans than Boots is to the British.
"There is a touch of that," admits Shepherdson. "But there is also an enormous respect for the British high street, which has more of a buzz and is less conservative than the American shopping scene."
It is perhaps this predisposition which has encouraged Tesco to announce that it will open some 250 convenience stores in California next year, using British shopkeeping skills to take on the likes of the famously aggressive indigenous supermarket chain, Wal-Mart.
"British retailing is at the top of its game," says Antony Miles, editor of cutting-edge fashion magazine '10'. "It captures the best of what American consumers like about British design and culture, and converts designs from the catwalk to the shop floor faster and better than anyone else.
"TopShop is one of the best examples of a vibrant British retailer, so it makes sense for them to be moving into the New York market right now."
He adds that appreciation of British fashion has reached an apogee, with the current Anglomania exhibition at the Metropolitan Museum of Art, the opening of which last Sunday was attended by Jane Shepherdson - a remarkable fact in itself.
American style landmarks are increasingly giving space to British tastemakers. Anna Wintour, the editor of US Vogue, and her creative director Grace Coddington, are both British, as are Harpers Bazaar editor-in-chief Glenda Bailey and Simon Doonan, the creative director of white-hot department store, Barneys New York.
"British celebrities and brands are in the ascendancy," says Miles. "Look at the obsession with the likes of Kate Moss and Sienna Miller. Then you think about how TopShop tries to recreate the things they wear, and it is easy to see how popular it would be among Manhattan shoppers."
Anglomania, whose opening gala dinner featured sausages and Yorkshire pudding as well as an ocean of tartan, courtesy of guest designer Alexander McQueen, brings together period costumes from the museum's collection with modern creative goliaths such as Dame Vivienne Westwood, John Galliano and Hussein Chalayan.
For the next four months, 'The Met' will exhibit the kind of clothes not seen outside Britain's stately homes and town centres - punks stomping on Chippendale tables, and a woman in a ball-gown about to smash through a window.
"The exhibition, and particularly the dinner, has given us an insight into how we are perceived in America," says Shepherdson. "Fashion is more real in Britain, it is something that arouses passionate interest and fierce competition among the shops.
"Wherever you go in Britain, knowledge and demand for the latest lines and accessories is phenomenal. We take a load of clothes to Shetland every now and then, to make sales in places where we don't have a permanent store, and they can't get enough of it.
"In America, the top-end shopping is more limited to the likes of New York and Los Angeles. Their perception of British fashion is that it has more of a street-level resonance that customers of all ages can find exciting."
She adds that British customers can be just as demanding as New Yorkers. "They want the very best, they know what styles they want and it has to be in the stores as quickly as possible. We are good at turning things around quickly - well you have to be, frankly."
What do the American shoppers want from us?
It may have become something of a clich in this country, but when Americans go to London they invariably head for the pedigree store, seen as a beacon of Englishness. Such is the importance of the dollar Harrods that it has even opened branches in Heathrow and Gatwick airports so tourists could pick up logoed teddy bears and keyrings before flying home. Jenners plays much the same role in Scotland.
• A nice cuppa
There's nothing more British than tea, and Twinings is hugely popular in America. Maybe it's the fact that it bears the Royal warrant, or that it's an integral part of the afternoon tea tradition that Americans love, but they just can't get enough of our English Breakfast bags. Over here, they flock to Fortnum & Mason to clink china - it makes a change from drinking out of cardboard in Starbucks.
• Snack attack
'Tartanised' products do enormously well in America: sales of Walkers' shortbread and Johnnie Walker whisky have flourished there. Carr's water biscuits, made in Carlisle, were a staple for British sailors on long voyages in the 19th century and were adopted on the other side of the Atlantic, where they remain popular.
• Wet-weather gear
Loved by the huntin', shootin', fishin' set, Hunters are a British institution. Last season's primary-coloured wellies may have won over young trendsetters, but the landed gentry's colour of choice is still muddy green. With no aristocracy of their own to mimic, Americans such as Madonna and Angelina Jolie have added a touch of class to their wardrobe by wearing them. Waxed or quilted Barbour jackets are also popular.
• A nice bit of cloth
Anglophiles (Madonna again) love a touch of Harris tweed, but its popularity has less to do with celebrity endorsement and more to do with America's obsession over their British roots. They may convince more people of their ancestry if they stuck with the traditional blazer, but some clearly don't get it: Nike limited edition Harris tweed trainers, anyone? Scottish cashmere - Johnson's of Elgin - lets uptown Manhattanites feel closer to the glens, even if they do wear them with pearls and Jimmy Choos.
• Cleaner carpets
An unlikely candidate, perhaps, but the hi-tech British dustsucker is a hit with houseproud Americans. Thanks to its appearances on TV shows such as Friends, one in five of all vacuum cleaners bought in the US is made by Dyson.
• Labels, labels, labels
Stella McCartney, Alexander McQueen and Nicole Farhi dominate the shop space in New York's trendy Meatpacking district. But it's the chance to buy into Britain's sartorial heritage that make Burberry and Aquascutum so popular - after all, if it was good enough for Humphrey Bogart in Casablanca, it's good enough for today's American style icons.