THREE hours into his marathon speech to the Communist Party congress in October, as delegates glanced surreptitiously at their watches, Xi Jinping, China’s president, sprang a surprise. “The practice of shuanggui,” he suddenly announced, “will be replaced by detention.” Shuanggui is a system in which party members accused of corruption are locked up in secret jails, beyond the reach of the judiciary and isolated from family or lawyers. In 2016 Human Rights Watch, an NGO, documented cases of beatings, sleep deprivation, stress positions and other forms of torture in shuanggui jails. That makes it sound as if Mr Xi’s unexpected move is a step forward for human rights. It may not be.

The abolition of shuanggui is the most visible part of a sweeping reform that in effect sets up an entirely new branch of government. Called the National Supervision Commission, it is designed to streamline administration, improve the implementation of policy and eliminate protectionist rules in the cities and provinces. A draft law governing the commission appeared in November; three provinces, Beijing, Zhejiang and Shanxi, have been giving it a trial run as it undergoes a public review. It is proving highly controversial, but is likely to get the go-ahead nationwide in March.

Unlike most countries, China has two pyramids of authority, the state and the Communist Party. High-ranking officials belong to both. Mr Xi is state president and general secretary of the party. The party hierarchy parallels the state one and outranks it. For example, the politburo, a party committee of 25, is more important than the state council, composed of government ministers. The shuanggui system belongs to the party. Ordinary jails, the police and the courts are parts of the state.

The new supervision system will be a mixture of the two. At the top is the new commission, which the law says will be led by the Communist Party and share space and personnel with the Central Commission for Discipline Inspection (CCDI). The CCDI is the party’s anti-corruption body and one of the most feared institutions in the country. It is responsible for Mr Xi’s purge of officials. Below the commission there will be a ladder of lower-level agencies that will work with courts and the procurators’ offices (ie, with the state judicial system). Like other government bodies, the agencies will report to the National People’s Congress, the rubber-stamp parliament, which is supposed to control them.

The new law would expand the CCDI’s powers. It will be allowed to investigate all officials, not just party members, and its mandate will include “improper conduct by state employees”, meaning that it will probe officials’ ethical standards and political beliefs, not just their compliance with the law. The new supervisors will be able to interrogate, search, wiretap, detain and punish suspects.

The extension of the graft-busters’ authority reflects Mr Xi’s belief that the current arrangement, in which the party is responsible for cracking down on corruption but only indirectly controls the police and judiciary, is no longer enough. The president’s concerns seem to have broadened from corruption to party discipline, ideological correctness and the need to clamp down on local officials who ignore the orders of the central government.

The new system is likely to intensify the anti-corruption campaign, to judge from the results of the three pilot schemes. In all of them, the number of cases handled shot up in the first eight months of the year compared with the same period in 2016 (when the old rules still applied), by 30% in Beijing, 40% in Shanxi, a province west of the capital, and 92% in Zhejiang, near Shanghai. Shanxi’s anti-corruption chief attributed the rise to efficiencies created by pooling the resources of party and state.

No smoke without some ire

A sense of the system’s likely impact comes from inspection tours organised this summer by the Ministry of Environmental Protection of factories in the north-east, China’s rust belt. The aim of such tours is to close down those that are exceeding legal limits on pollution. The ministry makes them all the time but its edicts are typically flouted. This time was different. Inspectors from the CCDI came along. Terrified polluters promptly closed dozens of foundries and smelters.

If an expanded CCDI can improve law enforcement in this way, then many business people, as well as those living in China’s most polluted places, will welcome the new system. But it is not clear whether it will improve the rule of law. What is really being abolished, says Jeremy Daum of the Paul Tsai China Centre at Yale Law School, is the pretence of the separation of party and state. Under the new system, suspects will not have the constitutional protection afforded to those accused of ordinary crimes. They will have no guaranteed access to a lawyer, for example, and though family members are supposed to be informed of an arrest, that requirement can be waived if it would hamper an investigation. Suspects can also be detained for longer than before: six months, not four. Jiang Ming’an, a professor at Peking University and a university friend of Li Keqiang, the prime minister, worries that the appeals system “does not seem effectively to protect the legal rights of detainees.” Chen Guangzhong of China University of Political Science and Law in Beijing argues that the legislature’s powers to supervise the supervisors need to be strengthened. He proposes a two-year nationwide trial to ensure due process.

Han Dayuan, the dean of the law school at Renmin University in Beijing, goes further, suggesting that the proposed system marks such a sweeping change that it requires a constitutional amendment. These concerns appear to be falling on deaf ears, however. Mr Xi has already given the system his seal of approval. The law is likely to be approved at the next meeting of the legislature, in March. The Communist Party’s authority is set to become even more entrenched.