Hong Kong: China threatens retaliation against UK for offer to Hongkongers

China has said it will take countermeasures against the UK should it grant residency to Hongkongers fleeing a harsh new national security law, promising that the UK would “bear all consequences”.

On Thursday, senior Chinese officials said the UK had no right to give residency to Hongkongers in response to Beijing forcing a sweeping anti-sedition law on the territory.

“China strongly condemns this and reserves the right to take further measures. The British side will bear all the consequences,” the foreign ministry spokesman, Zhao Lijian, said at a regular press briefing in Beijing.

Zhao’s comments came after the UK prime minister, Boris Johnson, said he would honour a promise to offer nearly 3 million residents of the former British colony, those with British national overseas status (BNO), the right to settle in the UK.

Earlier on Thursday, China’s ambassador to the UK, Liu Xiaoming, also said any move to grant residency to BNO holders would be a violation of agreements between the two countries.

It was clear that “all Chinese compatriots residing in Hong Kong are Chinese nationals, whether or not they are holders of the British dependent territories citizens passport or the British national (overseas) passport”, he said.

“If the British side makes unilateral changes to the relevant practice, it will breach its own position and pledges as well as international law.

“We firmly oppose this and reserve the right to take corresponding measures,” he said in a statement posted on the embassy’s website on Thursday. “The UK has no sovereignty, jurisdiction or right of ‘supervision’ over Hong Kong.”

Since the Hong Kong law went into effect late on Tuesday, at least 10 people have been arrested on national security related charges, including a 15-year old girl who waved a Hong Kong independence flag. On Wednesday, a total of almost 400 people were detained on other charges such as unlawful assembly, as thousands protested against the law.

Human rights advocates and residents, fearing the security legislation will be used to arrest protesters and pro-democracy activists, have called on countries to allow Hongkongers to seek refuge in their countries.

On Thursday, the Australian prime minister, Scott Morrison, said his country was working on a scheme to provide a safe haven to Hong Kong residents after China’s “very concerning” decision. Morrison said Australia was “prepared to step up and provide support”, although his cabinet was yet to finalise the details, including whether the scheme would include a pathway to permanent settlement.

The UK foreign secretary, Dominic Raab, has admitted there is little Britain can do to “coercively force” China if it tries to block Hongkongers from coming to the UK.

He told ITV’s Peston programme on Wednesday: “Ultimately if they follow through on something like that there would be little that we could do to coercively force them.”

Raab continued: “There is an issue around freedom and human rights in Hong Kong, and there is an issue around China keeping its word on an international obligation it made to the United Kingdom back in 1984.

“I wouldn’t want to be naive about this; I think we need to be realistic. But I do think that China as a rising, leading member of the international community is sensitive to the reputational risk in all of this, but clearly not sufficiently that it hasn’t proceeded anyway ... There is diplomatic leverage, there are other ways that we can persuade China not to fully implement either the national security law or some of the reprisals you talk about.

“But ultimately we need to be honest that we wouldn’t be able to force China to allow BNOs to come to the UK.”

Raab said he was working with other countries in the region to discuss a lifeboat operation. He said: “We think the majority will probably hunker down in Hong Kong, and others would leave to other countries in the region.”

The UK government believes the new security legislation passed by Beijing breaches the Sino-British joint declaration, which aimed to smooth the transition when the territory was handed back to China in 1997.

Johnson has said he will honour a promise to change immigration rules to allow holders of BNO passports, as well as those eligible for the passport, to reside in the UK and ultimately apply for citizenship.

As of February, there were nearly 350,000 BNO passport holders, while the government estimated there were around 2.9 million BNOs living in Hong Kong.

China has argued that a memorandum attached to the Sino-British joint declaration does not grant right of abode to those eligible for BNO status, but legal experts say the UK is not barred from extending their rights.

Related: Hong Kong protests over new security law – in pictures

Downing Street said those with BNO status would be eligible to travel to the UK immediately before the details of the scheme were finalised “in the coming weeks” and that they would not face salary thresholds.

The security law in Hong Kong, enacted late after an opaque legislative process that took less than six weeks, criminalises a broad swathe of behaviours deemed as secession, subversion, terrorism and collusion with foreign forces.

Critics say the law gives authorities sweeping new powers to crack down on dissent and a new level of Chinese control over the semi-autonomous territory.

Liu was summoned to the Foreign Office on Wednesday, where the permanent secretary, Sir Simon McDonald, told him the imposition of the new legislation on Hong Kong breached the Sino-British joint declaration.

Following his visit, Liu tweeted: “After turbulent months in the latter half of last year, the national security law will bring the order＆stability to Hong Kong and get its economy back on track.”

China views its actions as one of the last steps towards decolonisation, but an early test of its willingness to preserve the country’s freedoms will come in the autumn elections for the legislature.