BEIJING (Reuters) - China s Communist Party once shunned the rule of law, preferring to rely on what Chairman Mao Zedong called  rule of man    essentially using the authority of party leaders to govern. In recent years, though, as China s economy modernizes, the party has increasingly been turning to the law to exert central authority over the bureaucracy and keep citizens under control, according to legal experts and diplomats. And under President Xi Jinping, that trend has been accelerating, they say. Emblematic of that drive is a move to enshrine in law Xi s signature anti-graft campaign, which has ensnared nearly 1.4 million party members in the past five years. The move, announced last year, will be finalised at the Communist Party Congress that opens Wednesday.   Don t underestimate the importance of writing these things down,  says Jessica Batke, who covered China for the U.S. State Department and now writes on China s leadership for the Hoover Institution. Legal reforms are part of efforts by the Communist Party under Xi to grant more freedoms to ordinary people, while drawing red lines and creating harsher punishments for those who cross them, Batke said. Human rights groups often criticize China for only paying lip service to the rule of law and say the Communist Party systematically ignores due process when prosecuting activists and dissidents. Courts are being pushed by the Communist Party to be more accessible and fair in the hope that law becomes an effective tool to resolve disputes and stabilize society. But the reforms also help the leadership enforce central control by codifying previously informal restrictions, or campaigns like the anti-corruption drive, legal experts say.  What Xi is trying to do is centralize power in order to exert that power over China s unruly bureaucracy,  said Carl Minzer, a Chinese law expert at Fordham Law School in New York. Under Xi, the legislature has issued a flurry of new laws governing issues like internet controls, espionage and even how to sing the Chinese national anthem. New rules and laws are also being used to punish people who oppose the party, according to Maya Wang, a Hong Kong-based researcher for Human Rights Watch. The justice ministry has taken a tougher line on lawyers taking on rights cases. Last year it ordered law firms to  support Party activities,  which activists say raises the risks of taking on sensitive cases for lawyers. This month, Zhu Shengwu became the first lawyer to be stripped of his license for online posts critical of the Communist Party under the new measures. His posts had mocked the anti-corruption campaign and said the party was lawlessly administering justice.  Under Xi Jinping s rule of law reform, political and executive power has been legalized so as to erode the possibility of resistance,  said Fu Hualing, an expert on Chinese law at the University of Hong Kong. Xi s anti-corruption campaign will be overseen by a new National Supervision Commission, which will be given legal authority with a law still being drafted. The new body will take over from the Central Commission for Discipline Inspection (CCDI) and merge multiple anti-graft units into a single body, according to an announcement from the CCDI last year. It will also expand the graft campaign s purview to include employees at state-backed institutions. The CCDI, justice ministry and the National People s Congress, China s legislature, did not respond to requests for comment. The extent of the commission s power is closely tied to the fate of Wang Qishan, who has overseen the anti-graft campaign and is expected to stay in a leadership role despite being past the customary retirement age of 68, sources have told Reuters. Wang s exact position is likely to be made clear at the congress. One scenario would see him usher in the next phase of the graft fight as head of the super-ministry. Wang has said that the new commission should be granted detention powers by law, raising concerns among rights activists that practices like the informal detention of suspects for questioning could be validated. Rights groups consider the practice illegal and say that suspects are often tortured. Details about the commission are expected to be announced next year at an annual meeting of the National People s Congress, according to diplomats and legal experts. 