THE leader of the liberal faction, Mr Tian Jiyun, has boosted the ''supervisory functions'' of the National People's Congress over the Chinese Communist Party and the Government. Mr Tian, who was elected First Vice-Chairman of the NPC last week, vowed he would expose policies and actions of the party and Government that violated the constitution and the laws. His apparent bid to expand the powers of the NPC came on the heels of a speech by NPC Chairman Mr Qiao Shi on the need for China's parliament to check and balance the powers of the executive branch. Chinese newspapers yesterday quoted Mr Tian as telling leading journalists in the capital: ''We must further develop democracy and increase the people's supervision [over the party and Government]. This is very important for improving the work of both the NPC and the Government.'' The NPC Vice-Chairman, who is also a member of the Politburo, urged the nation's media to ''increase propaganda on the importance of following the constitution and the law''. ''Some of the classic instances [of government actions] against the constitution and the laws, provided they have been verified, can be publicised through the media,'' he added. The former vice-premier, who was once a right-hand-man of ousted party chief Mr Zhao Ziyang, called on the nation's journalists to increase their reporting on the legislative process and on the promotion of ''democracy and legality''. ''We should build up the system of stationing reporters [in the NPC] and strengthen the relationship between the congress and various media,'' Mr Tian said. ''The NPC should provide more clues and other conditions for journalists.'' Political observers in Beijing said it was the first time a senior NPC leader had called upon the media to help the legislature carry out its ''supervisory'' functions. They said given the clout and prestige of Mr Tian and Mr Qiao, there was a good chance that the congress could hold the party and Government to account over individual policy issues. However, since Beijing still stressed Communist Party leadership in all arenas of public life, it would be difficult for legislators to adopt Western-style measures of supervision such as impeachment of officials. While popular with the party's liberals, Mr Tian was passed over for the topmost echelon when he failed to get into the Politburo Standing Committee last October. Meanwhile, it was revealed yesterday that during the just-concluded session of the NPC and the Chinese People's Political Consultative Conference, the deputies put forward 4,569 proposals to government units. Most of these suggestions had to do with economic issues, especially cases of corruption and profiteering among cadres. Analysts said while the departments concerned were obliged to give a reply to the proposals, there was no guarantee concrete action would be taken.