A former chief justice of Canada’s supreme court is stepping down from Hong Kong’s top court, the city’s officials said Monday, the latest in a string of resignations from the court amid concerns about Hong Kong’s judicial independence.

Hong Kong’s judiciary confirmed late on Monday that Beverley McLachlin would end her term serving as a non-permanent overseas judge at Hong Kong’s court of final appeal.

The news came as a British judge who resigned from the same court last week warned that rule of law in the city was in “grave danger” and said judges were operating in an “impossible political environment created by China”.

Lord Sumption, who had served as a non-permanent overseas judge on Hong Kong’s court of final appeal, described a growing “paranoia of the authorities” and judges being intimidated by a “darkening political mood” in the Asian financial hub, in an article published by the Financial Times on Monday.

“Hong Kong, once a vibrant and politically diverse community, is slowly becoming a totalitarian state. The rule of law is profoundly compromised in any area about which the government feels strongly,” he wrote. “The least sign of dissent is treated as a call for revolution.”

He wrote that he had remained on the court in the hope that the presence of overseas judges would help sustain the rule of law, but “I fear that this is no longer realistic”.

McLachlin and Sumption were the latest of several overseas judges who have quit Hong Kong’s highest court in recent years.

Hong Kong, a former British colony, is a common law jurisdiction, unlike mainland China. Since the city returned to Chinese rule in 1997, non-permanent overseas judges have consistently served on its top court. 15 such judges served in 2019. About seven remain.

In 2022 another British judge, Robert Reed, stepped down while saying the administration “has departed from values of political freedom, and freedom of expression”.

Another judge, Lawrence Collins, resigned last week, telling the Associated Press that his departure was “because of the political situation in Hong Kong. But he said he continued “to have the fullest confidence in the court and the total independence of its members”.

Rights groups and critics say Chinese authorities’ enactment of a 2020 national security law has eroded Hong Kong’s judicial independence and all but wiped out public dissent. Many pro-democracy activists have been arrested under the law.

In May, a Hong Kong court found 14 pro-democracy activists guilty of conspiring to commit subversion in the city’s biggest national security case to date. They were among 47 activists accused of attempting to paralyse Hong Kong’s government and topple the city’s leader by securing the legislative majority necessary to indiscriminately veto budgets.

The Beijing and Hong Kong governments have insisted that the law has helped to bring back stability after huge anti-government protests in 2019.