The expertise of top barristers from overseas, parachuted into Hong Kong for important cases, has long been an asset to the city’s legal system. Their presence assists the courts in making complex decisions that may have far-reaching consequences. It was in this spirit that the Court of First Instance approved the hiring of David Perry QC to prosecute nine opposition figures accused of unlawful assembly. But the distinguished lawyer’s decision to act for the government sparked controversy in Britain. He came under fire from politicians and lawyers who viewed his move as supporting what they see as a crackdown on freedoms in Hong Kong. British Foreign Secretary Dominic Raab went so far as to brand Perry “mercenary” for taking the case, arguing his involvement would give Beijing a “serious PR coup”. The harsh criticism is unfair and misconceived. It undermines confidence in Hong Kong’s system of justice. Raab referred to the national security law. One of the defendants in the protest case, media tycoon Jimmy Lai Chee-ying, faces charges under that law in separate proceedings. Raab seemed to mix the two cases together. Perry was not asked to prosecute a security law case. The charges fall under the Public Order Ordinance. The defendants are accused of defying police and turning an authorised assembly into an illegal march on Central. The alleged offences took place amid the protests of 2019, before the security law was passed. The court, in approving Perry, said the case involved important constitutional issues of “unusual difficulty and complexity” relating to the right of free assembly. It was therefore in the public interest that this highly acclaimed overseas lawyer be admitted. The opportunity to hire a lawyer of similar standing should also be open to the defence. Perry’s decision to quit under pressure is not good for Hong Kong. It may prompt other overseas lawyers to shun the city for fear of coming under attack. The presence of a leading British barrister should have provided reassurance to anyone doubting whether the trial would be fair and free from political pressure. The government is entitled to hire overseas lawyers to represent it in exceptional cases. So are its opponents. This is an important element of Hong Kong’s legal system and should not be politicised.