China has said it reserves the right to take “corresponding measures” if the UK goes ahead with plans to give three million Hong Kong residents the chance to settle in the country.
On Wednesday, Boris Johnson confirmed a path to UK citizenship for those with British national overseas status (BNO), saying they would first be given limited leave to remain.
It came after the prime minister accused Beijing of a “clear and serious breach” of its treaty with Britain by imposing a much-criticised national security law in Hong Kong, which was a British colony until 1997.
The new law – which came into effect on Tuesday night – makes activities deemed subversive or secessionist punishable by imprisonment, and is seen as targeting anti-government demonstrators.
Around 370 people were arrested on Wednesday including a 24-year-old man accused of stabbing a police officer during a protest who was arrested on a London-bound flight before it took off.
But the Chinese Embassy in the UK said a move to give Hong Kong residents the chance to settle would be in breach of “international law and basic norms governing international relations”.
A statement said: “We firmly oppose this and reserve the right to take corresponding measures.
“We urge the British side to view objectively and fairly the national security legislation for Hong Kong, respect China’s position and concerns, refrain from interfering in Hong Kong affairs in any way.”
In a daily briefing, foreign ministry spokesman Zhao Lijian said China reserved the right to act against Britain over the issue, without specifying what countermeasures Beijing might take.
On Wednesday, foreign secretary Dominic Raab accused Beijing of a “grave and deeply disturbing” breach of the Sino-British treaty which “threatens the strangulation” of Hong Kong’s freedoms.
However, he admitted that the UK would not be able to force China to allow Hong Kong residents to come to the UK.
“There is diplomatic leverage,...