Hong Kong’s top officials have stepped up their defence of Beijing’s plan to impose a national security law on the city, saying the United States’ decision to revoke preferential treatment will not affect the stability of the Hong Kong dollar, and reiterating that only criminals need be concerned by the legislation.

Five ministers – the secretaries for administration, finance, mainland affairs, health and labour – on Sunday expressed their support for the central government’s plan to tailor-make legislation outlawing acts of acts of subversion, secession, terrorism or conspiring with foreign influences in the city.

The move has been strongly criticised by foreign politicians as a violation of the “one country, two systems” principle, but Hong Kong’s No 2 official, Matthew Cheung Kin-chung, chief secretary for administration, said those accusations were groundless.

“These countries hold double standards, as they have been advocating [the protection of] their own national security,” he argued.

“Who would object to plans to catch the thieves? The thieves themselves,” he said on a Commercial Radio programme.

“By having a home [without a] door, people can come in to steal and destroy. We’re only trying to install a door. Why, as neighbours, are you so worried and critical about it?’

In a Bloomberg editorial on Saturday, China’s ambassador to the United States, Cui Tiankai, said Beijing chose to enact the national security law after demonstrators became increasingly aggressive and “external forces” put the nation at risk.

Writing on her Facebook page on Sunday, Chief Executive Carrie Lam Cheng Yuet-ngor said she agreed with Cui that the legislation would “lay the groundwork for the practice of one country, two systems and Hong Kong’s long-term stability and development”.

But opposition politician Lee Cheuk-yan said on a television programme that by detailing plans to impose the law on Hong Kong, Beijing had broken promises made under the Sino-British Joint Declaration, a treaty registered at the United Nations which paved the way for the 1997 handover.

“Beijing is turning ‘one country, two systems’ into ‘one country, one system’ … the British government has the responsibility to lodge a complaint with the UN,” he said.

Singers Anthony Wong Yiu-ming and Denise Ho Wan-sze, both banned from the mainland since taking part in 2014’s Occupy Central protests, on Thursday said they were “shocked and angry” by Beijing’s decision, and were worried that the new law would infringe on freedom of expression.

But on Friday, more than 2,000 artists, including actor Jackie Chan, actress Liza Wang Ming-chun and international opera star Warren Mok, issued a joint statement in support of Beijing’s decision. They also urged authorities to engage various sectors and work to alleviate worries that freedom of expression might be in danger.

US Secretary of State Mike Pompeo on Wednesday said Beijing’s plan showed Hong Kong was “no longer autonomous” from mainland China. Two days later, President Donald Trump announced his government would revoke the trade exemptions now granted to Hong Kong.

As analysts said Trump’s options could range from individual sanctions and customs measures to currency exchange and visa restrictions, uncertainty in the city prompted panic buying of the US dollar on Friday. Worried Hong Kong residents rushed to banks to set up offshore accounts, while many also flocked to money changers.

The Hong Kong currency has been linked to the US dollar since 1983, and remained in the range of HK$7.75 to HK$7.85 to its American counterpart.

Writing on his official blog on Sunday, Financial Secretary Paul Chan Mo-po said the peg would not be affected by the national security legislation or US decisions.

“We need a sufficient amount of US dollars to maintain the system … and now our foreign exchange reserves are strong, with more than US$440 billion in assets. That’s equivalent to more than two times the foundation of Hong Kong’s currency,” he wrote.

“We also have the support from [mainland China] … Since the implementation of the system in 1983, it [the currency] has withstood various challenges.”

Chan also said Hong Kong would remain an international financial hub in Asia despite US actions.

“As China continues to deepen reforms and open up, its demands for financial services will be the firmest support and motivation in maintaining Hong Kong’s role as an international financial centre.”

He also said he believed the proposed legislation would help the city rebuild a stable and safe business environment, which had been undermined by the social unrest that erupted in June last year.

Writing on his official blog, Secretary for Labour and Welfare Law Chi-kwong argued that Beijing only decided to impose national security legislation because of separatist acts in Hong Kong and what he said was US interference in city affairs.

Secretary for Food and Health Sophia Chan Siu-chee, meanwhile, warned that the unlawful assemblies and violent protests that took place in recent weeks could increase the risk for the coronavirus to continue to spread in the community.

“Violent acts, such as arson and blocking of roads … showed the necessity and urgency of the national security legislation,” Chan wrote of recent protests against the law.

In a separate development, Basic Law Committee vice-chairwoman Maria Tam Wai-chu, who advises China’s legislature on Hong Kong’s mini-constitution, said Beijing’s legal experts would study foreign and local laws carefully to make sure that the new legislation protected residents’ rights.

“The new law is not for arresting and putting people in jail arbitrarily … Our Court of Final Appeal has explained clearly in many judgments how our freedoms are being protected,” she said.

Tam also reiterated the government’s stance that the new law would only target a small minority of radicals.