WHEN the Chinese Government cancelled the passport of Han Dongfang, leaving him a stateless person stranded in Hong Kong, the dissident labour leader turned to his friend Zhou Guoqiang, a lawyer who seems to specialise in impossible causes. At the moment, things do not look too good, admits Mr Zhou, a thin, garrulous 39-year-old. The worst-case scenario, he says, only half-joking, would be for Mr Han to be stuck in Hong Kong until 1997, when he should revert to Chinese sovereignty along with the rest of the territory. That is, unless the Chinese Government decides to take back Hong Kong ahead of schedule. By launching a suit against China's Public Security Ministry for deporting Mr Han and depriving him of his passport, Mr Zhou has hardly made himself popular with the authorities, and he is well aware that there are risks involved in challenging the leadership. Why does he bother to stick out his neck when the chances of winning are remote? ''Because Han Dongfang's beliefs and ours are the same,'' says Mr Zhou, interviewed in his tiny Beijing apartment decorated with a painting of three AK-47s and a quote from Mao Zedong - ''political power grows out of the barrel of a gun''. ''His affairs are my affairs,'' he says. Mr Han and Mr Zhou first met in May 1989, when the former emerged as leader of an independent trade union movement, and the latter led workers of his factory, the Beijing Acoustics Equipment Factory, into Tiananmen Square in support of the democracy rallies. Both men were jailed after the massacre - Mr Zhou for seven months, and Mr Han for two years. Mr Zhou, a computer buff and a poet in his spare time, used to be a technician. In 1985, his factory decided it needed legal advisers, and sent Mr Zhou and two others off to study law. Mr Zhou graduated three years later. Despite failing tests to qualify as a lawyer, and despite his political involvement, he remains a legal adviser for his factory, and says he is on good terms with the management there. Mr Zhou took up his first legal case in 1988, representing 400 athletes who signed up, after paying considerable registration fees, for a swim from the mainland to Hainan Island sponsored by a Beijing management school. The registration fees were supposed to cover all costs, but when the athletes turned up for the swim, they found that nothing had been organised and that they had to pay their accommodation fees a second time. Then, a notice was issued announcing the swim had been a grand success, although no one had swum a single stroke. The institute even issued certificates ''confirming'' the athletes' success. Mr Zhou, one of the swimmers, took the case to court. He claims the court was prejudiced towards the organisers and looked upon the athletes as trouble-makers. Four years later, the court ruled that the institute should grant compensation, but only to MrZhou and three others who personally appealed. They refuse to touch the money, insisting all 400 athletes should be compensated. Comparing the law suit to Mr Han's case, Mr Zhou says: ''There hasn't been any big change in the judicial situation.'' When he took Mr Han's suit to the Beijing Intermediary Court, he says: ''I thought it would be successful, because the judge told me: 'Please be assured we will do everything strictly according to the law. We won't be influenced by anyone, and will act independently'.'' In the end, the court refused to accept the suit, without giving any reasons. ''They simply said it did not meet the conditions of a suit,'' Mr Zhou says. He reckons that either the government directly intervened to put pressure on the court, or the court officials were worried that they would get into trouble if they decided to hear the case. ''It's not a question of law, but of the reality of politics,''says Mr Zhou. As things now stand, the Intermediary Court has passed on Mr Zhou's appeal to the Beijing Higher Court, which has two months to decide whether to accept the case. It seems unlikely that the higher court will oblige. In the meantime, Mr Zhou is not worried about his own status. ''If they really want to give me trouble, there's nothing I can do. But the trouble wouldn't be so big because I'm only an ordinary worker. I'm not a rich man. I don't have a great job, or career that I'm afraid of losing. I can do all sorts of technical work: lathe work, bench work, milling. At most I'll lose my job, but as a capable worker with some skills which all bosses need, I can find another job easily,'' he says.