IT ALWAYS claimed to put Hong Kong's interests first. The seemingly-respectable Democratic Alliance for the Betterment of Hong Kong (DAB), led by soft-spoken chairman Tsang Yok-sing, has been touted as the voice of reason in the leftist camp, since its formation last year. Even Governor Chris Patten apparently fell in love with it. He and his aides have been frequently heard to privately praise the party, describing its members as people they ''can do business with''. The DAB certainly put on a strong performance in its first year on the political scene, impressing the public with its efforts on Sino-Hong Kong grassroots issues, even persuading mainland authorities to abandon their controversial policy of random AIDS tests for frequent visitors. But lately the DAB's ''Hong Kong first'' image is starting to crack, amid allegations it changed its stance on one key issue, to keep in step with its ''masters'' in Beijing. Although DAB pleads this was due to a ''mistake'', its opponents have lost no time in labelling the move as the long-awaited proof the party is only Beijing's pawn on the Hong Kong political chessboard. ''Every important change on political matters by the DAB follows the direction and stance of the Chinese side,'' said United Democrat Cheung Man-kwong. ''They have failed to follow the feelings and interests of Hong Kong people.'' At issue is why the party changed its stance on the controversial through-train question, something which came to light after China declared its stance on the issue. DAB vice-chairman Tam Yiu-chung says it is right for objective criteria, on which legislators can straddle 1997, to be retrospective. But that is a complete turnaround on secretary Cheng Kai-nam's remarks in April, that such criteria should be ''measurable, predictable, consistent and non-retrospective legal articles''. Mr Tam has sought to explain away the about-face, insisting the party ''mixed something up''. ''We thought [the through-train] was a legal matter, so we made this conclusion in April,'' he said. ''But we later found out the issue was a political rather than legal one.'' Mr Cheng added that there had to be a learning process on any issue. However, United Democrats chairman Martin Lee Chu-ming believes the incident showed the DAB's independence was being undermined by Beijing. ''They have some good people and their hearts are for Hong Kong. But their policy on political matters is always stopped by China. This will be a big obstacle to their development,'' he said. ''Hong Kong people are very smart. If a party does things for China, they will lose points.'' Mr Tam denied the DAB was following in Beijing's footsteps over the through-train, saying: ''We do not have any new information on the talks.'' But he admitted that one of those who prompted the DAB to change its mind was Professor Wu Jianfan, the influential former Basic Law drafter and mainland legal expert: ''His suggestion is right. [The through-train] is a political check-in, and should notbe a legal matter.'' The DAB chairman also admitted its new stance, on retrospective criteria for the through-train, had been discussed with a Chinese official before being made public. ''I told [the official] about the problems of putting the term 'subversion' into the criteria from the through-train and he agreed,'' said Mr Tsang. The DAB's new stand says positive criteria should be used to judge if legislators can remain in office, instead of the negative term ''subversive activities'', proposed by China during the 15th round of negotiations in Beijing. But it also now believes the political check-in process should be retrospective, starting from the promulgation of the Basic Law in 1990. Mr Tsang said this showed the party was trying to lead, rather than follow, China's thinking: ''No one knows whether 'subversion' will be included in the [criteria for the] through-train. If it is excluded, then we can even claim that Beijing has followed our line.'' This is not the first time the party has faced problems in reconciling support for Hong Kong interests with its pro-China affiliations. When Chinese dissident Han Dongfang was expelled from the mainland in August, the DAB initially criticised the Chinese Government for its treatment of the labour activist, writing to Premier Li Peng, and calling for an explanation for Beijing's behaviour. But the party quickly dropped the issue, with Mr Tsang admitting it had come under pressure from hardline supporters. Another potential source of pressure for the DAB is its major donors - Chinese state-run enterprises, which contribute the bulk of the party's $5 million annual budget. But Mr Tsang said the DAB, despite strong backing from mainland firms, could only survive by pursuing independent policies. Mr Tsang admitted, however, the DAB would be in financial difficulties without the support of Chinese firms. ''The real reason they pay us is that they hope we can play a role in Hong Kong politics. If we are totally defeated in the 1995 elections, then we will be finished. So we cannot follow Beijing. ''We are pro-China, but we won't ignore the will of Hong Kong people and follow Beijing, because that would be suicide.'' But Mr Tsang said the party would never distance itself from the mainland: ''We cannot betray our integrity.'' This leaves the DAB torn between its loyalties to Hong Kong and Beijing. It also leaves it with a serious image problem if it wants to win public support and, more importantly, votes.