The Chinese government is set to revise a controversial system of imprisoning people in labor camps without trial, a potentially significant step towards legal reform promised by new Communist Party chief Xi Jinping.

Jiang Wei, the head of a government committee on judicial reform, said the government is preparing to reform the system known as “re-education through labor” but not abolish it, saying it “plays an important role in maintaining social order.”

The labor camp detention system, introduce in the 1950s, was previously meant for opponents of the communist regime but has been used by police to detain drug abusers, prostitutes and minor offenders for up to four years without trial.

Critics accuse the government of using forced labor camps to silence political activists, saying that the system undermines the rule of law and tramples civil rights.

China has 350 labor camps across the country with more than 160,000 prisoners, according to Xinhua.

But the reforms could only go as far as introducing procedural improvements, such as allowing defendants to get legal counsel and go to court, says Nicholas Bequelin, a researcher at New York-based advocacy group Human Rights Watch.

The reforms could only mean “a somewhat milder form on administrative detention” rather than abolishing the system, he told Reuters.