Britain will on Monday suspend its extradition treaty with Hong Kong in a further escalation of its dispute with China over the introduction of a security law in the former colony, British newspapers reported.
Foreign Secretary Dominic Raab, who on Sunday accused China of "gross" human rights violations, will announce the suspension of the treaty in parliament, the Times and Daily Telegraph newspapers said, citing sources.
Britain's foreign office declined to comment.
Such a move would be another nail in the coffin of what former Prime Minister David Cameron has cast as a "golden era" of ties with the world's second largest economy.
But London has been dismayed by a crackdown in Hong Kong and the perception that China did not tell the whole truth over the novel coronavirus outbreak.
Last week Prime Minister Boris Johnson ordered Huawei Technologies equipment to be purged completely from Britain's 5G network by the end of 2027.
China has accused Britain of pandering to the United States.
Earlier on Sunday, China's ambassador to Britain warned of a tough response if London attempted to sanction any of its officials, as some lawmakers in Johnson's Conservative Party have demanded.
"If UK government goes that far to impose sanctions on any individual in China, China will certainly make a resolute response to it," Liu Xiaoming told the BBC's Andrew Marr Show.
"You've seen what happens in the United States - they sanction Chinese officials, we sanction their senators, their officials. I do not want to see this tit-for-tat happen in... China-UK relations."
Raab told the same programme he would not be drawn on future additions to Britain's sanctions list but he denied that Britain would be too weak to challenge China through this channel.
Britain says the new national security law breaches agreements made before the 1997 handover of Hong Kong to Chinese rule, and that China is crushing the freedoms that have helped make Hong Kong one of the world's biggest financial hubs.
Hong Kong and Beijing officials have said the law is vital to plug holes in national security defences exposed by recent protests. China has repeatedly told Western powers to stop meddling in Hong Kong's affairs.