MI5 Chief Expresses Frustration Over Collapsed China Spy Trial in UK

MI5 Chief Laments Failure to Prosecute China Spies

Sir Ken McCallum, the Director-General of MI5, has publicly expressed his 'frustration' following the collapse of a high-profile espionage trial involving two British men accused of spying for China. Speaking on Thursday, October 16, 2025, McCallum acknowledged the extensive efforts by the security service to secure convictions in such cases, stating, 'it's frustrating when they don't happen.'

The MI5 chief's remarks come amidst a deepening controversy surrounding the decision by the Crown Prosecution Service (CPS) to drop charges against former parliamentary researcher Christopher Cash and academic Christopher Berry last month. Both men, who consistently denied any wrongdoing, were accused of providing information 'useful to an enemy' and 'prejudicial to the safety or interests' of the United Kingdom between late 2021 and February 2023, under the Official Secrets Act 1911.

Government's Stance on China Cited in Case Collapse

The primary reason for the trial's collapse, as stated by Director of Public Prosecutions Stephen Parkinson, was the government's inability to provide evidence that China represented a 'threat to national security' at the time the alleged offenses occurred. This requirement stemmed from a High Court judgment in a separate Russian spying case, which clarified that for prosecutions under the 1911 Official Secrets Act, the accused's actions must be for a country deemed an 'enemy' at the time.

Despite witness statements from Deputy National Security Adviser Matthew Collins detailing China's 'large scale espionage' and its intelligence agencies harming 'the interests and security of the UK,' these were deemed insufficient by the CPS. Collins' statements also emphasized the government's commitment to pursuing a 'positive relationship' with Beijing, which complicated the legal definition of China as an 'enemy' for the purposes of the prosecution.

Political Fallout and Ongoing Threats

The collapse of the trial has ignited a political dispute, with the current Labour government, led by Prime Minister Keir Starmer, and the opposition Conservative Party trading accusations. Starmer maintained that the government could not provide the testimony because the previous Conservative administration, in power during the alleged spying period, had not designated China as a 'threat' but rather an 'epoch-defining challenge.' Conversely, Conservatives have accused Labour of allowing the case to fail to protect economic ties with China.

Sir Ken McCallum underscored MI5's unwavering stance, asserting that 'Chinese state actors' pose a 'UK national security threat' every day. He highlighted various forms of Beijing-backed meddling, including cyber espionage, technology theft, covert interference in public life, and the harassment of dissidents. McCallum also revealed that MI5 had disrupted a China-linked espionage operation as recently as the past week and noted a 35% increase in individuals under investigation for state threat activity over the last year. The Chinese Embassy in London has dismissed the allegations as 'fabricated' and 'malicious slander.'