THE expansion of Hongkong's representation on China's legislature, the National People's Congress (NPC), from 18 to 28 seats was not unexpected. With less than 41/2 years to go before the territory reverts to Chinese control, it is a timely recognition of the political weight Hongkong deserves to carry in the affairs of the nation. Together with the five representatives from Macau, Hongkong deputies will, for the first time, have sufficient numbers to propose a motion at the NPC. Although the NPC's reputation as a rubber-stamp body might make Hongkong's new status appear something of a back-handed compliment, it does add to the future Special Administrative Region's voice and credibility in councils of state. At a time when relations between China and Britain are tense over the pace of Hongkong political reforms, there is no mistaking the ulterior motives behind this boost to Hongkong's prestige. Each of the delegates ''elected'' to the mainland parliament isreliably pro-China. Many have strong links with pro-Beijing organisations in Hongkong or vital business interests in China which would make them think twice about expressing alternative views. Had these been contested elections, in which Hongkong people had a real say, it is doubtful whether the 28 Hongkong delegates would have rated so highly. Few of the newcomers are well-known names. New Hongkong Alliance (NHKA) member Mr Kan Fook-yee, for instance, made his mark defending the Beijing position on the Basic Law. Others have no known local following or power base. NHKA chairman Mr Wai Kee-shun is a veteran sports and public affairs commentator. Mr Huang Diyan, arguably one of the most senior mainland representatives in Hongkong, is the director of the Hongkong and Macau office of the Bank of China. While some such as Mr Kan and Airport Consultative Committee maverick Mr Victor Sit Fung-shuen have shown considerable political ability in taking the offensive to promote pro-Beijing positions, others have yet to show their political skills. Their appointment to the NPC may be the first stage in China's efforts to start grooming Hongkong people for positions of influence after 1997. If China is preparing to set up an alternative political structure to the Legislative Council - ''to set up another stove'', as the quaint metaphor has it - it needs some experienced operators able to outshine the increasingly sophisticated directly elected elements in Legco. Hongkong law still prohibits simultaneous membership of both legislatures; so with some of the most skilled pro-China politicians seemingly aiming for seats in Legco in 1995, Beijing is having to find new talent fast. Once the crunch comes, however, Beijing will be ready. The prohibition on cross membership is unlikely to last. The five-year term of the new batch of NPC delegates ensures that they, unlike their Legislative Council counterparts, are guaranteed to ride the ''through-train''. They could be in place without further election to serve as ''elected'' members of the post-1997 legislature and to replace those liberals that Beijing finds unacceptable. Those who believe such tactics are too crude even for Beijing should study the response of NPC veteran and chief editor of the China-controlled Ta Kung Pao newspaper Mr Tsang Tak-sing to Mr Martin Lee Chu-ming's remarks that the new delegates were not genuine Hongkong representatives because they were not elected by Hongkong people. His claim that election by Chinese people on Chinese soil made them more representative than Mr Lee who was ''not elected by Chinese nationals in China'' will be regarded withscepticism locally. What the NPC elections do represent is China's interpretation of the patriotism and loyalty that it demands of Hongkong delegates to the NPC and ultimately of Hongkong people. In the light of the current row over the Governor's proposed electoral reforms, it will be interesting to see if Beijing is still prepared to consider appointing members of liberal political groups other than the United Democrats among its next batch of Hongkong advisers next month.