It’s still dark outside when the troops gather. Dressed in the armour of the modern high street – skinny jeans, Converse trainers or knee-high boots, scarves draped artfully around their necks – they look scarcely equal to the fight ahead.

The battleground is Topshop, Oxford Circus, on Saturday, December 15 – the biggest fashion store in the world, on what has been predicted to be the busiest day in its history. And the battle facing these young shopworkers is a staggering one.

Today, in the space of 13 hours, some 50,000 shoppers will push through Topshop’s doors. They will swamp the store’s 100,000 sq ft of floorspace. They will try on hundreds of thousands of items. They will be monitored by 200 cameras and 24 security guards, and at the 120 cash registers they will make almost 32,000 transactions (a 34 per cent increase on a normal Saturday). Others will not bother paying at all. The 300 members of staff will rush to keep up.

At the head of the operation is Lucy Somani, the store’s 28-year-old manager. She has been in the job for just ten weeks, but seems fearless about the day ahead. “We’re having a record week,” she says, “and it’s going to be the biggest Saturday we’ve ever seen today. It’s fast in here anyway – we can sell out of a line within an hour – but today it’s going to be even faster. It’s really, really exciting.” She points to her high-heeled shoes. “These will be off by 11 o’clock.”

Every day, at 9am on the dot, the same piece of music is played over the speakers to let staff know that the store is open. The iconic synth-stabs from the film Kill Bill blare out. The song, more appropriate today than ever, is called Battle Without Honour or Humanity.

Spread over three vast floors, Topshop, Oxford Circus incorporates a hair salon, a nail parlour, an eyebrow bar, make-up stations, a maternity-wear shop, a baby shop, concessions by designers such as Zandra Rhodes, Celia Birtwell and Kate Moss, a café, and a sweet shop that would put Willy Wonka to shame. In Topshop parlance, not only does the store count as its own “region” but its takings – about £110 million a year – easily exceed those of any of the other Topshop regions (the North, the South and the Midlands).

The store is filling up. Over in one corner, manning the information desk, 20-year-old Binny Enver is bracing herself for a barrage of “stupid questions”. She has worked at the store for three years. “It will get stressful,” she says. “The queries will be never-ending, but you get through it and it’s a buzz at the end of the day.”

Near by, in the sorting room, 22-year-old Linda Gorczynska just knows that she will end the day exhausted. She deals with the clothes rejected by customers after much wriggling and preening in the store’s 200 changing rooms. It’s 10am and already the items are piling up.

“To be honest, I’m a bit anxious,” she says. “I’m confident that we’ll handle it, but soon the whole place will be full of clothes and we’ll be stressed to the limit.”

Gorczynska will spend the next seven hours rehanging and refolding clothes as fast as she can. It is not an enviable job for £6.50 an hour.

By midday it is becoming hard to move. Herds of tweenagers in black leggings and Ugg-style boots or ballet pumps fill their shopping bags with yet more black leggings, Ugg-style boots and ballet pumps. Big-haired, skinny-legged fashionistas swoop on the new spring/summer Jet Set line, which commandeers pride of place on the shop floor (Topshop is “done with Christmas,” proclaims Laura Vickery, the assistant manager of the main clothes floor). Meanwhile, hesitant tourists stand at the edges of the throng, looking terrified.

Megan van den Bergh, 19, is from California and on holiday in London with a friend. She looks lost. “My friend heard about Topshop and we thought we’d check it out,” she says. “It’s not my kind of thing. It’s too much stuff . . . too many clothes.”

“Too much!” echo a Dutch family, as they huddle together by the escalator shaft.

Jacob Okuma, 37, does not even try to navigate the store by himself. He is on a 12-hour stopover, on his way from America to Nigeria for his sister’s nuptials. He wants to buy her a wedding present. Pulling his wheelie suitcase behind him, he marches over to the first sales assistant he sees. “I want diamonds. Big diamonds!” he declares. Half an hour later, he leaves with a very “bling” imitation gold necklace and earrings.

Just off the shop floor, in a cramped room piled high with boxes labelled “wigs”, “dress pins”, “feathers”, “beads” and “baubles”, are Sarah Lennon, 25, and WaiLing Wong, 26. Members of the store’s creative team, they are normally in charge of the mannequins and window displays. Today they are on repair duty.

“Customers knock over mannequins, take them off their stands and just drop them, strip them of their clothes . . .” says Sarah. For the time being, her task is just to keep up with the destruction.

In the security control room, the chaos of the day unfolds across nine CCTV screens. Every inch of the store is covered by cameras, each of which can turn full circle and has a zoom function so powerful that the person monitoring it can read the time on a customer’s watch. The guards on camera duty know exactly what they are looking for.

“They will know within 20 seconds whether a person is up to no good,” says Gurhan Evlat, head of security. “There’s no shoplifting stereotype. As far as we’re concerned, anyone is a potential thief. It’s the body language – the eyes, the signs that people give off – that give it away.”

Evlat drops a pile of pliers, scissors and burnt electronic clothes tags on the table – all evidence of the UK’s £1.5 billion shop theft industry. In the past four weeks, he and his team have prevented goods worth more than £10,000 from being stolen. There are, on average, about 50 attempted thefts a week at Topshop, Oxford Circus.

Today’s first incident happens at 1.08pm. Two young Eastern European women enter the store. They are clearly not here to shop. They move quickly – too quickly – among the racks, grabbing items at random without checking the size or price. Their heads are moving constantly here and there, seeking out the security cameras.

The footage is extraordinary. The women hold up items of clothing to shield their hands as they delve into the bags and pockets of other customers. Several times they find themselves being dragged along, hands still searching, as their victim walks away.

“This is an absolute ‘job on’,” says Evlat. Guards on the shop floor are alerted and the women are manhandled into two instore holding rooms while the security team waits for the police to arrive.

The operation is carried out smoothly, and the other customers remain oblivious. They are far more concerned with battling their way from lingerie to knitwear, finding the last size 10 and queueing for the complimentary gift-wrap service, where Anna Nicola, 26, is looking increasingly frazzled.

Her hair, perfectly coiffed this morning, is now scraped back into a ponytail. Scraps of paper and Sellotape cling to her clothes. “Normally I find myself standing here for about an hour doing nothing,” she says wistfully, as she wraps five nail files and bottles of nail polish for 14-year-old Aoife Corbett. “Today we haven’t stopped.”

By 3pm the crush to get into the store is five people deep. Inside, it is stiflingly hot and hard to move. Philip Green, owner of the Arcadia Group, the umbrella company that controls Topshop, and holder of the No 7 slot in the Sunday Times Rich List 2007, pays a surprise visit. No one recognises him. He plucks some sweets from his sweet shop and gives them to a young boy. “Oh no, no, I think we should really pay for them,” says the boy’s mother, unsure what to make of this strange, sweet-stealing man.

Around the corner, through a back entrance, the fourth stock delivery of the day arrives. First to be unloaded are 69 boxes packed with shoes, bags and jewellery. Then come 1,600 skirts, shirts and dresses. They are placed on moving rails, attached to the ceiling, which take them directly to one of seven stockrooms, to join more than 300,000 other pieces of clothing.

Overseeing the delivery is Mark Denner, the logistics manager. He spouts numbers. On top of its 100,000 sq ft of shop floor, Topshop, Oxford Circus has 11,000 sq ft of stockroom space. Today, it will receive 16,500 items of clothing in six deliveries. There are about 200,000 coat hangers in circulation around the store. Last week, Denner ordered a consignment of 95,550 shopping bags.

Above the shop floor, in the cash office, Prince Boateng is not so forthcoming. He is waiting anxiously for the return of a “Charley run”, in which staff wearing protective glasses “in case someone wants to spray their eyes with pepper spray – or perfume” push a metal safe around the store to collect the takings from every till.

He refuses to say how much money he is expecting to be taken, but “it will be more today than any other day. If we started counting it today we wouldn’t be going home tonight”. Instead, the money will be placed overnight in safes with doors 8in (20cm) thick, and he and his team of eight will begin counting it at 9.30am tomorrow. They will not be finished until 3pm.

By 6.30pm the worst is over. The crowds have thinned and snapped tags litter the floor. Hangers are left at odd angles, mannequins stand disrobed.

“Yeah, it has been crazier than most Saturdays,” admits sales assistant Matt Cutler, 19, as he begins the clean-up.

In the sorting room, Gorczynska is almost hidden under clothes: “Usually we try to empty the sorting room by the end of the day,” she says. “But today . . .”

There are still 15 minutes left until closing time at 10pm. “I’ve got no money left!” squeaks a young teenager in shorts, a beret and mustard-coloured pumps, as she trips to the till to make a last purchase at 9.50pm.

At 9.55pm, a fed-up boyfriend has to drag his girlfriend bodily out of the store. She gazes back longingly.

At 10pm exactly, we hear the familiar notes of Battle Without Honour or Humanity. The battle is over and, with or without honour or humanity, it has been won.

Hitting the rails at Christmas

–– In 1992, Topman and Topshop combined forces at 214 Oxford Circus to create the world’s largest fashion store, which is visited by 200,000 shoppers a week.
–– The store sells 30 pairs of knickers a minute, and 40,000 vests each week.
–– On December 1, Christmas shoppers spent more than £100 million in London, when three of the capital’s busiest shopping streets were closed to traffic.
–– In 2006, shoppers withdrew £1 million a minute from cash machines nationwide on the Friday before Christmas.
–– Shoplifters will steal an estimated £431 million worth of goods in the build-up to Christmas. Their main targets are alcohol, perfume, womenswear and cosmetics.
–– In 2006, Britons clocked up online sales of £7.66 billion in the run-up to Christmas.

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