Under the nearly three-decade-old system, police have unilateral power to detain sex workers and their clients for up to two years in “shelter and education” centres.

Critics say the centres have little to do with education.

“There may be resistance inside the regime against abolition, perhaps by the police, as this would take away some of its arbitrary detention powers,” said Wang Yaqiu, a researcher at Human Rights Watch.

In 2013, testimonies of ex-detainees collected by Asia Catalyst – an organisation that defends the health of marginalised groups in the region – revealed the harsh living conditions in the centres.

These included ill-treatment, forced labour, and the obligation to pay for subsistence and forced medical examinations at prohibitive prices.

“All this is a matter of money, the talk of rehabilitation or ideological education is hollow, it is just a way of extorting money on behalf of the state and the police,” one of the women told the group.

Shen Chunyao, chairman of the NPC Standing Committee’s legislative affairs commission, said in December that “the time has come to begin the work of abolition”.

“In recent years, the use of the detention and education system has gradually decreased, the number of people in the centres has clearly diminished and they have been banned in some places,” Shen said.

Discussion over the future of the centres came after China’s top legislative committee abolished its system of “re-education through labour camps”, known as laojiao, in 2013.

Shutting the labour camps – introduced more than half a century ago as a speedy way to handle petty offenders – closed the curtain on a dark aspect of the country’s modern history long criticised by human rights groups and which Chinese officials admitted was no longer viable.

That prompted a rare instance of dissent from state media, which questioned the system.

Getting rid of the detention centres would be “a very positive step for the rule of law in China”, said Shen Tingting, director of advocacy and policy at Asia Catalyst.

Although illegal, prostitution remains widespread in China, with an estimated several million sex workers.

Many living in Beijing were driven out with migrant workers as part of a demolition campaign in the city’s slums in 2017.

“Today they are in the suburbs, isolated, with no place to work. They go online and go to the customer’s house, it’s very dangerous,” Shen said.

She said the existing legal arsenal was already “sufficient” – prostitutes and their clients can be fined up to 5,000 yuan (US$745) and face up to 15 days of administrative detention.

But Shen is unconvinced that attitudes towards sex workers will change, even if the forced re-education of prostitutes eventually disappears.

“The repression will continue and one wonders what new system [could] replace the old one,” she said.