In London's Chinatown, workers blend quietly into communities
After the tragic death of at least 21 Chinese cocklers and subsequent manslaughter trial, new laws to licence gangmasters have come into effect.
The cocklers' fate in Morecambe Bay highlighted the plight of illegal immigrants in the UK and the often appalling conditions in which they live and work.
The drownings created a shockwave reminiscent of that following the suffocation, in the back of a lorry, of 58 Chinese people attempting to enter Britain in June 2000.
Those desperate enough to try to enter the UK illegally contact smuggling gangs, run by Chinese criminals known as snakeheads, to get them in.
Many then find themselves working for unscrupulous employers, or forced into criminal activity, to make ends meet in the UK.
To avoid a repeat situation of Morecambe Bay, where "gangmaster" Lin Liang Ren provided his fellow Chinese with dreadful living conditions and then failed to alert authorities to impending disaster, the government has introduced new legislation.
From Thursday, 6 April, the Gangmasters Licensing Authority(GLA) will officially licence suppliers and hirers of labour.
Licences will be required for the supply of workers to agriculture, horticulture and processing and packaging of any produce derived from agriculture, fish or shellfish.
The aim is to "help bona fide labour providers stay legal by driving out those who undercut them by exploiting or mistreating workers".
But, despite this official protection, it appears there are many jobs that will remain "underground" and will be carried out by a hidden army of Chinese immigrants - many illegally in the UK.
Many of them work in poor conditions, live in rotten accommodation, and risk the constant threat of arrest or harassment.
And many, unable to speak English, have taken the drastic step of leaving their families behind in China, to try and solve their financial problems by working illegally in the UK.
"I have an 18-year-old daughter; she is at the end of her high school term and is applying for university," 35-year-old Mrs Zhang says.
"But we cannot support her any more and have had to come here to the UK to earn money for her."
Mrs Zhang sells illegal cigarettes full-time in Chinatown in London; she has being doing this since she sneaked into the UK six months ago.
The Zhang couple started getting into debt after she paid money to "oil the wheels" and get her husband out of jail, following a dispute with the Chinese authorities over the "one child policy".
She says: "Although we worked hard, at the end of the month we could still not fill the hole in our debt."
One Chinese man survived the cockler disaster in Morecambe Bay
However, they learned that a friend from their town had cleared his debts and brought a lot of money home by working in the UK.
In desperation they were introduced to a snakehead and Mr Zhang decided to come to the UK.
First the couple borrowed 250,000 yuan (£20,000) from the snakehead for his journey. The deposit was their daughter.
Mr Zhang arrived in London 18 months ago to work in a Chinatown restaurant. His life was difficult but the money came quickly.
Later they figured that if Mrs Zhang came too then the payback time would shrink by half, from 12 years to six years, while their daughter's university fees would be sorted.
"I cannot see her graduation which is four years from now, but I think I can be there when she gets married," she says.
She sells cigarettes in Chinatown, even though she is often ill. The couple live on just £2 daily, except for rent and travelling.
Like many Chinese, the Zhang's have not benefited from the recent economic boom in China, which has been enjoyed by the middle class city dwellers.
However, even Ling Ling, a 55-year-old from booming Shanghai, prefers to stay working in the UK black economy.
She hands out promotional leaflets for restaurants in Chinatown, and is often close to exhaustion from walking the streets.
Some illegal Chinese immigrants sell pirate DVDs in pubs and streets
Ling Ling came here legally to join her husband a year ago, a man she met in Hong Kong who had told her how great life was in the UK. He had a British passport due to Hong Kong being a former UK colony.
But once here she was treated as a free maid, and only allowed to take a shower once a week.
She separated from her husband six months ago, lives alone, and works in Chinatown to support her life here.
"I have confidence in myself to learn the language, and take root in this country - and create a better world for myself," she says.
Many immigrants come to the UK out of despair just to stay economically alive. But there are others who see a chance to use their money-making talents.
Louis has experience of financial successes in China from the mid-1990s by taking advantage of the privatisation of state assets.
He says he was smuggled into the UK by snakeheads, via Russia, Ukraine, Slovakia, Germany and France.
Louis saw companions beaten brutally because their families in China could not pay their travelling fees on time.
"From the start of the journey, I only had one thought: get to London as soon as possible," he says.
However, this one-time businessman has found life selling pirate DVDs on London's streets harder than he imagined.
Job risks include avoiding the police, defending himself from muggers, and being drunkenly abused.
"Right now I live with 11 other people in the same two-bedroom flat," he says.
"Some have the same job as me, selling DVDs, and some work in restaurants."
He adds: "I want to go back to China as soon as I can, later this year or early next year. London life is hell for me."
However for now, he will stay and earn some more money to help him care for his 11-year-old daughter who he has left behind in China.
Ahead of the gangmaster licensing, Defra Minister Lord Bach said: "The key aim of licensing is to protect the most vulnerable workers by ensuring that labour providers operate within the
But for now many vulnerable immigrants will continue to try working outside the law in the UK, to earn a living for themselves and families back in China.
The identities of those interviewed have been changed.