PRESIDENT Jiang Zemin has strengthened his stranglehold over Beijing's party apparatus and reminded the city's leadership it should learn a 'sombre lesson' from the downfall of former boss Chen Xitong. Mr Jiang was reported yesterday by Xinhua (the New China News Agency) to have made an unprecedented three-day, high-profile inspection in Beijing. In addition to talks with the city's beleaguered leadership, he visited a defence technology exhibition, a machinery factory and even joined the Beijing cadres to take part in the construction of an irrigation project. During his visit to the defence show, he was accompanied by a number of political heavyweights including Vice-Premier Zhu Rongji and General Zhang Zhen of the Central Military Commission. But Mr Jiang did not visit the model enterprise, Capital Iron and Steel, as his patron Deng Xiaoping did three years ago. The evening news last night was full of reports about his Beijing sojourn and his meeting with foreign ambassadors. Chen was arrested in April this year and stripped of his posts on the Politburo, Central Committee and National People's Congress for his role in covering up the crimes of his protege vice-mayor Wang Baosen, who committed suicide rather than face a corruption investigation. In Mr Jiang's meeting with the Beijing leaders, he told them they should 'learn a sombre lesson' from Chen's case and 'turn a bad thing into a good thing'. Speaking to an enlarged meeting of the Beijing party committee, he said the municipal party and Government should unify in thought and deed and make a fresh start in the drive for economic development. It was important, Mr Jiang said, to 'draw a clear line between the broad mass of cadres and Chen Xitong and Wang Baosen'. 'The reason why I am here is to lend my support to the mass public and cadres in Beijing . . . I hope we can unite together and forge ahead,' he said. But he also made a veiled criticism on their former boss, saying the present leadership should take the initiative in liaising with the central Government over their work. Chen, elevated to the helm of the Beijing apparatus 12 years ago, had been criticised for his arrogance and reluctance to co-operate with the central leadership. Mr Jiang told the meeting attended by the new party chief, Wei Jianxing, Mayor Li Qiyan and Executive Vice-Mayor Zhang Baifa, they should firmly toe the party line. Analysts said the President used the meeting to re-establish his central authority over the party committee, which under Chen Xitong had routinely contradicted or ignored his orders. He was also letting senior officials in the municipal party know they would be spared from any future investigation as long as they continued to toe the party line, analysts said. Before the meeting, political sources said Vice-Mayor Zhang had been forced to write a self-criticism, acknowledge his mistakes and return to the city property and money he had allegedly misappropriated. 'They were all looking very sheepish during Jiang's lecture,' a political analyst said. 'I think they all got the message loud and clear.'