All asylum seekers arriving in Hong Kong are to be screened by the government under a mechanism starting in March, a year after the Court of Final Appeal forced a rethink on the issue.
Currently, the Immigration Department screens people who claim to be escaping torture, and the UN High Commissioner for Refugees screens refugee claims.
The top court ruled in March last year that the government could not simply rely on the UNHCR to decide whether someone was a refugee, and must assess all cases independently and fairly.
The Immigration Department will take responsibility for assessing all such claims, and the UN refugee agency, which has run the screening programme for asylum claimants, will have no further role.
However, leading human-rights lawyers say the new process has been rushed in and lacks detail about transitional arrangements for the fate of existing torture claimants in the city.
Refugee advocates had been complaining for years that the lack of a unified system caused long delays because asylum and torture claims often overlapped.
In a statement yesterday, the government said all "non-refoulement" cases - those claiming that expulsion or extradition would expose them to risks - would be handled under the new Unified Screening Mechanism (USM) from March 3.
It said the new process would "meet with the high standards of fairness required by law, and at the same time prevent abuse by economic migrants who aim to protract their unlawful stay in Hong Kong".
But human-rights lawyer Mark Daly said: "In my view, there has been no consultation, no independent scrutiny of these procedures." Fellow lawyer Mark Sutherland agreed that the measure had been fast-tracked without proper consultation.
Another rights lawyer, Robert Tibbo, noted it had taken more than a year for the Security Bureau to act on the Court of Final Appeal ruling in December 2012 known as the Ubamaka judgment - after Nigerian Edward Ubamaka, who unsuccessfully fought a deportation order - and more than three years after the Bar Association called for a unified screening mechanism.
He added: "I hope that all the torture claims that are ongoing are included in the USM."
The government said there would be suitable arrangements for previous torture claimants.
The Security Bureau said it handled 491 torture claims last year, and is processing 2,590.
The city's policy of not granting asylum to anyone will remain in force. People granted refugee status in Hong Kong are resettled elsewhere.