LONDON (AP) — The United Nations’ former human rights chief and eight former U.N. special envoys urged the body’s secretary-general Thursday to appoint a special envoy on Hong Kong, saying they are deeply concerned about a potential “humanitarian tragedy” as Beijing prepares to impose draconian national security laws on the city.

Zeid Raad Al-Hussein, who was the U.N. High Commissioner for Human Rights during 2014-2018, and the eight former special rapporteurs called for the unusual procedure because of the “severity of the deterioration, the impending grave threats under the new security law, (and) the symbolism that a human rights crisis in what had been one of Asia’s freest cities entails.”

A law that could be enacted as soon as next week would criminalize secession, subversion of state power, terrorist activities and colluding with foreign forces to endanger national security.

The central government in Beijing also would set up a national security office in Hong Kong to collect and analyze intelligence and deal with criminal cases related to national security. The plans have not been officially published, and details were only gleaned from a state media report.

The proposals have been widely seen as the most significant erosion to date of Hong Kong’s high degree of autonomy promised under the “one country, two systems” principle since Britain returned the former colony to China in 1997.

“We believe there are now very real fears of a human rights and humanitarian tragedy in Hong Kong,” the former U.N. officials’ statement said. “It is imperative that the international community, and particularly the United Nations and its member states, act urgently to establish a mechanism for observing, monitoring and reporting on the human rights and humanitarian situation in Hong Kong.”

Former British Foreign Secretary Malcolm Rifkind said Thursday’s move sends a powerful message and signals that the crisis in Hong Kong has grown from a mostly local dispute to an international one.

“From the Chinese government’s point of view that is a disaster,” he told The Associated Press. “It’s the last thing they would want. And yet it’s going to get much worse from their point of view, because if this is all happening before they try to apply this new law, imagine what the reaction is going to be if they start to extradite people.”

However, he acknowledged that it would be much more difficult to take further action within the U.N. because of the Chinese veto in the Security Council.

Lawmakers and senior politicians in the U.K., U.S., European Union and elsewhere have been considering options to join forces and push for collective action should Beijing go ahead and enact the law.

Rifkind and Chris Patten, the last British governor of Hong Kong, recently led a grouping of more than 900 international parliamentarians from 43 countries in decrying Beijing’s law. He was also among seven former British foreign secretaries who have urged Prime Minister Boris Johnson to take a stronger leadership role and coordinate an international contact group on the topic.

“We have a legal obligation to raise these matters. But we are not naïve, we recognize the U.K. by itself will only have limited influence,” Rifkind said. “We hope the cumulative effect will persuade (President) Xi Jinping that whatever his aspirations in Hong Kong ... the government elite will lose more than it will gain.”