The foreign judges who sit part-time on Hong Kong’s top court were like canaries in a coal mine, one of them said in 2017. So long as they are happy to serve, it can safely be assumed all is well with the city’s judicial independence. But if they leave in droves, it would be a “serious alarm call”. The judge who delivered that speech, Lord Neuberger, last month agreed to renew his three-year term on the court. Two other judges, from Britain and Australia, also extended their contracts. Their decision is a sign of confidence. But it has fuelled much debate in Britain, where calls for its judges to pull out of Hong Kong have mounted. Senior members of the opposition Labour Party have joined The Times in arguing that the judges should withdraw. Their presence, it is said, provides Hong Kong’s system with an appearance of legitimacy no longer warranted following the passing of the national security law, arrest of opposition activists and impending electoral reforms. The president of Britain’s Supreme Court, Lord Reed, told parliament he would consider stepping down as a Hong Kong judge if there was any undermining of the city’s independent judiciary or rule of law. British officials and judges are discussing the issue. A role for overseas judges on the Court of Final Appeal was part of the arrangements put in place for Hong Kong’s return to China in 1997. The foreign judges, all distinguished and highly experienced, have played an indispensable part in building the reputation of the top court. They bring expertise, a fresh perspective and keep the city’s courts in touch with developments in the common law world. Their withdrawal from Hong Kong would be catastrophic. Hong Kong courts free of government meddling, justice minister says Hong Kong is going through a period of political change as Beijing acts on perceived threats to national security and seeks to ensure only “patriots” govern Hong Kong. But judicial independence remains intact. One of the British judges, Lord Sumption, wrote a letter to The Times commending the courage of Hong Kong’s judges and their commitment to judicial independence. As he said, Britain should support rather than abandon the city’s judiciary. Lord Neuberger stated in his 2017 speech that a time might come when a judge feels he or she cannot in all conscience remain in office. As Chief Executive Carrie Lam Cheng Yuet-ngor has noted, that time has not arrived in Hong Kong. But the position of overseas – and local – judges could become untenable if judicial independence is eroded. Every effort must, therefore, be made to preserve it. Britain will be letting down Hong Kong’s judiciary and weakening the city’s ability to uphold core values of the legal system, including human rights, if it withdraws judges from Hong Kong. It should pull back from the brink. The canaries are still safe to sit in the coal mine – and to sing loudly if they perceive any threats to their independence.