A British barrister has agreed to act for the Hong Kong government next month in its efforts to convict Jimmy Lai and eight other pro-democracy activists accused of taking part in an illegal assembly in 2019. David Perry’s decision has been challenged by the chair of the foreign affairs select committee, Tom Tugendhat, and by the Labour peer Lord Adonis. Perry – who has been approached for comment – is regarded as one of the most formidable British QCs to operate in Hong Kong, and will be advising the courts on how the activists broke the city’s freedom of assembly laws. The maximum sentence is seven years if the case is heard in the district court. Hong Kong’s court of first instance on Tuesday granted the justice department’s application to fly in Perry to handle the case, noting not only its complexity but its “real and significant impact on the exercise of the freedom of assembly in the future”. The case against the activists revolves around an anti-government protest on 18 August 2019. Prosecutors claim the protesters disregarded police orders by turning an approved assembly inside Victoria Park into a march that was not permitted. Among the other defendants are “Father of Democracy” Martin Lee Chu-ming, the Tiananmen Square vigil organiser Lee Cheuk-yan, and the veteran activist “Long Hair” Leung Kwok-hung. All nine defendants were charged jointly with two offences: organising an unauthorised assembly and knowingly taking part in an unauthorised assembly. The trial has been set for 16 February. Amid a worsening crackdown on dissent in Hong Kong, China imposed a national security law on the territory in June last year. Last week, in by far the largest action so far taken under the law, more than 50 people, including pro-democracy politicians and campaigners, were arrested in early morning raids. On Sunday, the foreign ministers of Australia, the US, Britain and Canada issued a joint statement expressing “serious concern” about the raids. “It is clear that the national security law is being used to eliminate dissent and opposing political views”, the countries’ four foreign ministers said. Overseas barristers require special high court approval before they can practise in Hong Kong on an ad hoc basis, and are mainly used if external advice is needed for complex cases. Perry’s hiring was first reported in the South China Morning Post. Tugendhat, the chair of the Conservative China Research Group, said: “We all need to ask when the law stops being an instrument of justice and becomes the tool of tyrants. Hong Kong’s new security law suggests we are beyond the point when we can ignore the question and the implications for everyone working in the legal process.” Adonis tweeted: “Where are the ethics of the English legal profession going?” Barristers justify acting for parties on the principle that justice must be available for all, and Perry has long experience in the Hong Kong courts. In December, the UK foreign secretary, Dominic Raab, said he had started consultations with Lord Reed, the president of the UK supreme court, about the appropriateness of British judges sitting as non-permanent judges on the Hong Kong court of final appeal. Several British judges sit as non-permanent members on the court, and Reed has been a personal advocate of their continued presence, partly on the basis the judges can help maintain the court’s independence from the Chinese state. Lai, a 73-year-old media tycoon, is facing multiple other charges, including some brought under the new national security law, including colluding with foreign powers. The controversy came as a coalition of 36 civil society organisations launched an appeal to European commissioners to demand the inclusion of enforceable human rights clauses in the EU-China trade deal agreed just after Christmas. The coalition said the omission of a specific human rights clause “sends a signal that the European Union will push for closer cooperation [with China] regardless of the scale and severity of human rights abuses carried out by the Chinese Communist party, even when Beijing is in direct and open violation of international treaties and continues to refuse to allow international monitoring of the human rights situation”. The investment agreement, which has led to protests from the incoming administration of Joe Biden in the US, has yet to be ratified by the European parliament.