It was nearly lunchtime and couples were sauntering arm in arm through the part of London known as Chinatown, deciding which restaurant to enter. The spacious, airy one with white tablecloths? The cosier one with the glazed ducks hanging in the window?

A small group of tourists opted for the elegantly decorated Gerrard’s Corner, singled out in dining guides for its authentic cuisine. When I followed them in, a Chinese waiter swiftly guided me to a table and politely asked what I’d like to drink.

After he’d darted off, I watched his movements. He never stopped. Customers came in; he smiled, sat them down, took orders, brought drinks, brought food, smiled again, took more orders. For a moment, when nobody was demanding his attention, he stood still; but the manager nudged him to go back to the door. So he darted off, smile back in place.

When he came back to pour my tea, I asked him in Mandarin how much he was paid. Holding the teapot in his hand to justify talking to me for longer than he should, he said in a low voice: “We’re paid £5 a day, as a base rate. That’s all we earn if we don’t get any tips.”

That daily £5 is the sole reward his employer gives him for working 11-12 hours a day, six days a week. This wage structure, I discovered during discreet chats with waiters in the following weeks, is in place in 99% of the restaurants in Chinatown. While the businesses pride themselves on being a tourist attraction, they are leaving it to customers to compensate for the pittance they pay their staff.

But that is not the full story. Waiters, as the “front face” of restaurants, tend at least to have legal status to live and work in Britain. But behind this front is the concealed foundation of the Chinese catering trade: the workers without documents who work in the airless kitchens or stand with placards in the street as “greeters” in the rain or do deliveries on bikes or unload lorries or silently push dim sum trolleys.

Without their toil, most of the 5,000 Chinese restaurants and the 10,000 Chinese takeaways in Britain would go out of business.

Despite their dependence on this army of undocumented labour, few restaurateurs in Chinatown are willing to talk about it. So I decided that the only way to get a true picture of the working life of an illegal worker was to pretend to be one.

Last June, I was told that Chuen Cheng Ku restaurant in Wardour Street — which is popular for its food trolleys — had vacancies. So I walked in and asked for a job — any job.

The manager asked the manageress of the dim sum trolley waitressing team to speak to me. A severe-looking woman in her forties, she introduced herself as Hao Jie, the Good Older Sister. I told her I was on a student visa (which permits you to work for a maximum of 20 hours a week) but was willing to work any hours.

“From Monday to Friday your hours are 11am to 4pm,” she said. “At weekends 11am to 5.30pm.” I nodded enthusiastically. She handed me two sheets of dim sum menu and told me to memorise all the items before I started work the next day. King prawn dumplings, pork dumplings, bean-curd rolls, phoenix feet (chicken feet), sea snail, beef tripe, spare ribs, lotus seed buns . . . there were about 30 items on the list. “You’ll be paid £3.20 per hour,” she said. “If you work at night, you’ll get £3.50. You’ll need to pay a deposit of £20 for your uniform, and £30 to ensure you won’t leave the job without giving two weeks’ notice.” I also had to buy my own black skirt to go with the restaurant’s uniform: a traditional Chinese bright red top.

My job title was tui che (trolley-pusher); but when I arrived, I found I’d be called by the name of the food on my trolley. Henceforth, I would be known as Roast Duck.

Hao Jie did not explain where things were in the kitchen, let alone warn us about safety hazards. She simply told us all to load food onto our trolleys. Xiao Ying, a worker who’d started the day before, was opening the lid of each steamer, trying to remember the names of the dishes. She spoke no English, so this required great effort.

My trolley was the heaviest, carrying not only roast ducks but also roast pork, roast chicken and a large pot of congee with fermented eggs and pork threads. With all this weight, it was hard to manoeuvre it round the corners of the room. I grimaced as I passed Xiao Ying, and she whispered to me that her feet were in agony from standing all day yesterday. “I’ve put a bit of toilet paper between my foot and my shoe. But I’m still limping.”

From noon, tourists and businessmen started to arrive in large numbers. As soon as they sat down, all seven trolley-pushers — with me at the back — rushed towards them, one after the other, touting our wares. By the time I reached the tables, people’s plates were overloaded with food from the other trolleys. On that first shift, I managed to sell only 12 plates.

When we ran out of dishes, we had to rush into the kitchen to collect new ones. Then we heated food — uncovered — in the greasy microwave. There was no time to cover it, apparently. I was instructed to spread oil on the roast ducks so the birds would look as if they’d just come out of the oven. This technique worked well: customers always looked impressed.

After the first three hours of walking around, I desperately needed to sit down. But there were no breaks. You had to push the trolley around without stopping, even when there were hardly any customers.

The only place where we could sit was on the toilet, and it was there that I managed to have quick chats with some of the workers. Xiao Ying told me that this was her first job in England. She had no idea that £3.20 an hour was an extremely poor wage. Another worker, from Guangdong province, had taken the job because, without papers or resources, she didn’t know what else to do.

At 3.50pm, 10 minutes before the end of my shift, the team leader asked me: “Are you okay with this job?” I thought she was being kind, so I told her I was fine and thanked her. She then asked me to start tomorrow.

I thought I’d started today. My feet certainly told me so. I asked Xiao Ying what the team leader had meant. “It means you’re not going to get paid for today’s work,” she told me. I was indignant. I went up to the Good Older Sister and asked her: “Hao Jie, am I going to get paid for today’s work?” “No,” she answered with a frown. “This is your learning day.” Before leaving, I was told to clean the trolley in the kitchen. I had to take all the plastic doors off it and wash them in the sink — the same one used for all the dishes.

When I pitched up at 10.30 the next day, I noticed that the other workers stated their time of arrival as 11am, even though they’d also arrived at 10.30. This, I found, was another small way to pay the workers less. Hao Jie explained that 11am was the time we actually started serving customers, so that was the time from which we got paid. Nobody seemed to question this. In fact, nobody questioned the restaurant about wages at all. We were being paid £16 for a day shift, and that was that.

Xiao Ying, who is in her early twenties, was discovering that the money didn’t go far. “I spent almost £3 on transport getting here and back. It’s hardly worth the while!” she said. After spending £10 on a skirt and shoes for the job, and paying the £50 deposit, she was almost penniless.

But she had no choice. She owes £20,000 to a moneylender in China — money she borrowed to come to work in this “first-rate country” (without first-rate pay). I expect that she’ll be spending the next decade labouring in workplaces like this — if she avoids being rounded up and deported.

The rest of our trolley team was also made up of undocumented workers, eager to get on any shift for any reward. The employers hadn’t even asked for our contact details. They knew we’d come back.

In the eyes of the management, we were nothing but cheap, statusless labourers whose work could be taken for granted. The way we were given our food was an example of this basic contempt. The waiters in this restaurant were allowed to eat from plates. We trolley workers, however, were fed in a different way. In the morning, just before the shift began, meat and vegetables were poured into one deep metal container for all of us to eat from with chopsticks.

I found that after the food had been flipped over by six other trolley workers searching for the better morsels, I’d lost my appetite. But nobody complains about this cattle-trough feeding technique. Xiao Ying, I noticed, wolfed the food down, chewing hard and loud, trying to amass the energy she needed to get through the next shift. Eat and work, eat and work again: that’s the rhythm of life for trolley workers.

By the end of that day, I had blisters on my feet. The next morning, I felt asthmatic, so I called Hao Jie to tell her I was off sick. “Don’t you realise it’s Friday? We need you to come in today!” she barked at me down the phone. And she hung up on me. On Sunday evening, when I called her to confirm my shift for Monday, she said: “You’re not going to take a day off again this week.”

She had definitely taken against me — a troublemaker who asked too many questions and took days off. I noticed she tried to humiliate me in front of my colleagues by changing rules and blaming me for not remembering them. There was no point in arguing. Nobody talked back. Nobody even dared support a co-worker in an argument.

At the end of the shift, I was paid my wages from last week: £16, sealed in a plastic bag. At the bottom of the bag were the words: “Reusable: please return.” The job sickened me, literally and metaphorically. But I could leave; sadly, my co-workers could not.

I changed into my own clothes in the staff toilet. As I walked towards the front door, the waitress took me for a customer. She smiled warmly and opened the door for me, saying: “Goodbye. Come again!”

But a woman standing next to her had recognised me. “She’s one of the trolley-pushers,” she told her colleague. In an instant, the waitress had let go of the door and wiped the smile from her face.

- When I asked the management at Chuen Cheng Ku restaurant and Gerrard’s Corner restaurant for their comments, they did not respond

© Hsiao-Hung Pai 2008

Extracted from Chinese Whispers: The True Story Behind Britain’s Hidden Army of Labour by Hsiao-Hung Pai, to be published by Penguin on Wednesday at £8.99. Copies can be ordered for £8.54, including postage, from The Sunday Times BooksFirst on 0870 165 8585

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