Han Dongfang could be one of the new generation of sharp young entrepreneurs bred by China's gold-rush economy. A trendy-looking 31, he would be quite easy to picture doing deals on a mobile phone in Shanghai or Peking, content to go along with a Communist Party that says greed is good. Yet the authorities consider him so dangerous that they have illegally expelled him from his own country.

What the businessman he might be has for sale is cheap labour. China's export boom is founded upon low wages, long hours and a minimalist approach to health and safety. As the son of a peasant and a building labourer, and leader of the country's first free trade union, Mr Han challenges the Communists' claims to represent the working class, an issue so sensitive that he is far more threatening to Peking than dissident middle-class intellectuals.

Unlike the student leaders who fled abroad in 1989 after the Chinese authorities crushed their democracy movement, Han Dongfang has never been to university, even though there is no doubting his ability. One factor bringing him into confrontation with the authorities was that he could not bear their continual insults to his intelligence. Until the demonstrations began in Peking, he was a railwayman with a troublesome reputation who had no idea that there were others who thought as he did.

Mr Han stands out because he brings home how wide class divisions are in China, more than four decades after Communism was supposed to have abolished them. 'Look at how severely workers were punished after Tiananmen,' he points out. 'They were sentenced to death or up to 15 years' hard labour, while none of the student leaders received more than seven years.' The Workers' Autonomous Federation, which he helped to found, is little more than a collection of brave individuals attempting to keep alive the principle of free trade unionism under constant persecution. Its ideas, however, are spreading, as is workers' frustration, if the number of wildcat strikes and outbreaks of labour violence are any guide. From Hong Kong, Mr Han continues to campaign against China's official trade unions, which are mere instruments of Communist Party control. He is visiting Europe to persuade union movements here to have nothing to do with them, and to urge them to intervene on behalf of independent labour organisers who were detained in a sweep earlier this year.

'You don't speak out in China because everyone is isolated, especially if you are a worker,' he says. 'You are confronted by the machinery of the work unit, the Gong An (Public Security Bureau), the official trade unions. Whoever challenges them gets hurt.'

He speaks from experience: nearly half of one of his lungs is missing, thanks to the tuberculosis he contracted during more than two years in detention. Having gravitated towards the marketplace of ideas in Tiananmen Square, he was on 'most wanted' list when the troops were sent in. Characteristically, he refused to go into hiding and gave himself up.

Shortly after he was freed in 1992, the government allowed him to go to the US for medical treatment. Now it refuses to let him back into China. He has tried three times to return, getting as far as Canton on the first occasion before the Gong An grabbed him and shoved him back into Hong Kong.

Why has China effectively made Mr Han stateless? One reason is his persistence. After Tiananmen, more privileged dissidents were silenced by threatening their employment prospects or university places, or simply by parental pressure. Others have given up head-on confrontation and opted to go into business, where they are relatively free from interference. They can even console themselves that, by contributing to economic growth, they are loosening many of the controls pervading Chinese life.

Han Dongfang's road to dissent, however, was longer and lonelier than that of a university undergraduate. 'I come from a poor background,' he says. 'All my youth I experienced the pain of being at the bottom of society.' He first began to see the gap between Communist rhetoric and reality in the People's Liberation Army (PLA), which he joined at 16.

'There was huge discrimination between officers and men. We had to contribute to the officers' food budget, so that they ate much better than we did. As a squad leader I tried to negotiate on behalf of the men, which was the first time I got into trouble. At that time I still believed in the system, just that there were some bad elements in it. I applied to join the Communist Party, but was blocked.'

Mr Han does not conceal the fact that he might not have wound up in opposition to the party had he become a member. But in a way that makes him more of a threat, because his motives are far more understandable to ordinary Chinese than student yearnings for peace and freedom. It was the same when he joined the railways as an electrician - he is a natural leader to whom others looked for help with their complaints. But the main cause of his falling out with his superiors was their refusal to allow him to change shifts to be with his dying mother.

'We would go out of Peking on the trains for a month at a time. My colleagues would grumble that they couldn't manage on their wages, which had not been increased for years. Finally I said: 'It's no good just complaining. We must raise this at the monthly meeting when we get back.' But when we did, the party official in charge said: 'How dare you] For 30 years the party has known best.' '

Mr Han clashed with the same man when his mother's health was failing. 'Other people gave him gifts, or used connections to get favours from him, but I refused. I went to the official union for help, but the union cadre said he was powerless - he reported to the same official.' It was suggested that he should apologise in public to the official, but Mr Han insisted on being allowed to address the meeting, and 'somehow it kept being postponed'. By the time of the democracy movement, his frustration had led to another row, during which he threatened to beat up a section head. He might have remained an obscure and somewhat nave young rebel, had it not been for Tiananmen.

The Workers' Autonomous Federation, which emerged out of the unrest, has given him a platform, and exile has smoothed his edges, but he persists in his infuriating refusal to play by the Chinese state's rules. Anybody else would have recognised that, having been permitted to leave for America, he was meant to stay there. The masses accept that the Chinese constitution's guarantees of free speech and the right of labour to organise are simply rhetoric, but he insists on trying to apply them.

Journalists groping for parallels have labelled him 'China's Lech Walesa', but he complains: 'This has given me nothing but trouble, because the Chinese government really believes I present a political threat. I have always said we are not seeking to overthrow the political system, simply to achieve free collective bargaining. We can't be an underground movement or an exile movement, because we must organise among the workers.'

To the Chinese leadership, such words are lethal. Here, perhaps, is the main reason Han Dongfang has been singled out. To those old revolutionaries still living, his determination to hold a corrupt system to account reminds them of nothing more than their younger selves.

(Photograph omitted)