There is an odd moment when shopping, with which most readers will probably be familiar. It's that second when you're standing in Tesco/Primark/Asda fingering (for example) a £20 sequinned top, and into your head pops the image of an exhausted woman, head bent, sewing on each of those sequins. The glitter of the top dims a little.

You might put it back. Or you might reassure yourself that we are no longer in the Victorian era of labour sweatshops - don't most companies these days sign up to some ethical code or other? - and head for the till.

Well, there is an ethical code. It's called the Ethical Trading Initiative (ETI). But as the past few months have shown there are serious doubts as to how much this means. In October an undercover investigation for Channel 4 turned up evidence that suppliers for Tesco - one of the ETI's founding members - were using child labour, an allegation that Tesco refutes.

Then last week anti-poverty campaigners at War on Want released a report about the conditions and pay of Bangladeshi workers supplying Asda, Primark (also ETI members) and Tesco. It did not paint a pretty picture. Again, all three companies vigorously defended their ethical position.

Many anti-poverty campaigners have nice things to say about the ETI (although one woman laughs when I mention it and someone else sighs). But there are some serious flaws in the set-up, and these are only going to become more problematic.

The ETI lives and dies by its admirable "base code", a list of fundamental principles such as the right to a living wage (ie, a wage on which you can support yourself and your family), the right to safe, hygienic working conditions and the abhorrence of child labour. But one of the biggest problems is that, although any companies signing up to the ETI must sign up to the base code, they are not committing themselves to living by those principles, only to working towards them. There is a big difference.

Companies that sign up are using their membership as a sort of endorsement, as if it guarantees something in the way the Soil Association logo or the Fairtrade mark do.

Take Primark: it resisted signing up to the initiative until this year. Then the ETI released a joyful press release announcing that the chain was planning to "provide till notices for interested customers that set out the company's commitment to continually improving working conditions in its suppliers' factories". (So already Primark was visualising its ETI membership as in-store advertising for its ethical credentials.)

Then, when Primark's name came up in the War on Want report, its response - and implied defence - was that "as members of the Ethical Trading Initiative we are fully committed to the campaign to improve working standards in Bangladesh". The ETI becomes a sort of shield.

And what happens if you are proven to have come in under par? The ETI does not seem to deal in public rebukes or summary ejections. There is a procedure should it be necessary to remove a company from the list, but the head of communications at the ETI cannot remember if any company has ever been chucked out.

In a brave exercise this year the ETI got an independent organisation to measure whether it had actually achieved anything. In some ways the results could be interpreted positively: major improvements in areas such as health and safety and working hours by ETI companies were recorded. But looked at more harshly, the results might be perceived less favourably: with 90 categories, there were major improvements in only 12, after 10 years of work.

Anti-poverty worker Deborah Doane of Core, the Corporate Responsibility Coalition, thinks that the ETI was important when it started up, as a forum for people to talk about all these things. "But it has focused too much on the voluntary bit - the pat on the back mechanism - without looking at what you need to change this picture. The companies which signed up haven't done as much as they should."

Some companies really are trying to improve, but others are proving to be brilliant at what are seen as cosmetic ethical initiatives - using organic cotton, starting up Fairtrade T-shirt ranges - all of which create an undeserved rosy glow around the industry.

In fact, conditions are worsening for many workers in Bangladesh, China and other developing countries, and more bad news will be emerging over the next few months.

Our obsession with cheap, trendy clothes means that retailers push suppliers to offer them lower and lower prices (something similar happens in the food industry). One supplier was quoted in the independent report on the ETI as saying that "they struggled to meet this element of the base code [non-excessive working hours] due to the need to meet tight production deadlines with short lead times". It is only fair to point out that even if the ETI is ludicrously weak, in the end it is the companies that need to take action.

And campaigners in this area seem to agree that the only way to get the big companies to change at this point is regulation and legislation. If we are depending just on voluntary codes and self-regulation, it is going to be slow progress.

For now, working conditions are still sunk in the 19th century, except that the sweatshops are that much further away.

So is there any way of ensuring that you are not supporting sweatshop labour?

For a start, you can support any ethical clothing initiatives by the big companies; that's what will encourage them to keep going. Besides that, buy from small companies, buy second-hand clothes, apply pressure yourself . . . not much of an answer, really. Especially if you're a garment worker in Bangladesh.

Today, child camel jockeys are not allowed in Dubai any more, because of a prolonged campaign by Anti-Slavery International, one of the charities featured in The Independent's Christmas Appeal this year. Campaigning to change the law, and advocacy on behalf of vulnerable people, is one of the key aspects of the agency's work.

But such advocacy is not yet over, according to Tanveer Jahan of Anti-Slavery International's local partner in Pakistan, the Democratic Commission for Human Development (DCHD).

The town of Rahim Yar Khan sits on the edge of the desert. It is a dirt-poor sort of place but dotted around the town are several palatial residences. Those are the hunting lodges of wealthy Arabs from the Gulf states, who come here to hunt the abundant wildlife of Pakistan's desert. But, according to Ms Jahan, that is not all they hunt.

They also employ local agents to find children to work as camel jockeys. The use of children may have been banned in Dubai and the rest of the United Arab Emirates but that is not the end of the story. Before the ban, there were believed to be 3,000 child jockeys in the UAE - most of them from Pakistan, Bangladesh and Sudan. But only 1,000 ever returned home.

No one knows what happened to the others, but the use of child jockeys has not been banned in all countries. And, according to Ms Jahan, they are still recruiting in Rahim Yar Khan.

Children are favoured as jockeys because they are small and light enough not to slow the camels. But the conditions they face are grim. Mubasher Hussain was sold by his parents when he was seven years old. Today, aged 12 and safely back in Pakistan, he tells his story in the sunny garden of the government school where he is catching up on lost years.

"My parents told me they were going to perform the Haj [the pilgrimage to Mecca], but they took me to Dubai," he says. "There was a sheikh, Mohammed Khalifa. My parents gave me to him. They told me to stay with the sheikh while they performed the Haj but they didn't go. My father got a job in Dubai, working in a slaughterhouse."

That is a common arrangement, according to Ms Jahan. The camel owners agree to arrange visas for the whole family if they sell one son as a jockey. As Ms Jahan puts it: "The child is the main bargaining chip".

For the family, it is an opportunity to work in Dubai, where they can earn far more than at home. But for the child, it is the start of a nightmare.

"I spent one month learning to ride the camels. When I fell off, the supervisor used to beat me, sometimes with a stick. I was scared on the camel. I was very high up and the camel went very fast. But after I learned how to ride I was not so scared.

"We worked every day from before dawn till eight at night. In the morning we had to feed the camels and clean the stables. When it got hot in the middle of the day we had to move the camels to the shade. In the afternoon we had a couple of hours to play.

"Then in the evenings we had to practice riding. I got to see my parents once a week. I was allowed to go and visit them.

"They gave us very little food. The sheikh wanted to keep us small for riding the camels, so they wouldn't give us enough. I was hungry most of the time, but my brother used to sneak some food to me in the night."

Still Mubasher is one of the lucky ones. He never fell in a race and he escaped serious injury.

Nasir Hussain, no relation, was not so lucky. He was sold at the age of five. He fell off the camel in the middle of a race and was trampled. "I was terrified," he says. "My father was there watching the race and he ran on to the course to save me. My leg was badly hurt so he picked me up and carried me off the course.

"They took me to the hospital. I was told the sheikh paid my hospital bills but he never came to the hospital. No one from the camel stables came."

Today Nasir is seven years old. His leg is still badly damaged. It is much shorter than the other, and he walks with a severe limp that will never go away. His toes have splayed out unnaturally to support his weight. After the accident, his parents were able to bring him back to Pakistan without any objection from the camel owner. But for Mubasher, who was never injured, it was not so easy.

"After two years my parents went to the sheikh and told him they wanted to take me back to Pakistan," he says.

"He refused. So my parents went to the police. They raided the stables and rescued me. The supervisor who used to beat me, who was named Akil, spent 15 days in prison. The police took me to my parents, and they brought me back to Pakistan."

But the problems do not end with the children's return to Pakistan. During their time as camel jockeys, they do not go to school. When he returned to Pakistan at the age of nine, Mubasher could not read or write.

He could not even do simple maths sums. As a result of campaigning by Anti-Slavery International and DCHD, the Pakistani government has agreed to a special programme to help the camel jockeys catch up in schools. They are given extra tuition in special classes to help them make up the lost time, and a small scholarship of 600 rupees (£6) a month.

According to government figures, 336 children returned to Pakistan, but Ms Jahan says her organisation's research shows the real number is closer to 600. "Some are kidnapped and smuggled, but most are sold by their parents," she says.

"They sell them because of poverty. If a family has five or six children they will sacrifice one for the others. But it's all a pipe dream: they don't get much money. Most of the money goes to the agent who finds the child. And the child's life is totally ruined."

For Ms Jahan, the struggle goes on. She is determined to track down where the thousands of missing child camel jockeys have gone, now the practise is banned in the UAE, and get them home. She also wants to win the returned children more financial support.

"A lot of these children who have fallen off the camels need reconstructive plastic surgery for their injuries," she says. "But you can't get plastic surgery for 600 rupees a month."

The school where Nasir and Amir are learning today is a dusty open yard. There is no school building and the children sit in the hot sun on the ground. This is a government school but there is not enough money for anything more.

When we ask Nasir which he prefers, Pakistan or Dubai, where he was abused and terribly injured in his fall from a camel, his answer is surprising. "Dubai," he says. When we ask why, his answer is simple. "There is electricity there. And good buildings."

In the corner, Amir sits silently. No one knows how he feels about Dubai, where he lost one eye, and the ability to speak.