The collapse of a high-profile China spy trial has triggered intense cross-party pressure on the director of public prosecutions (DPP), Stephen Parkinson, to provide a comprehensive explanation. MI5, the UK's security service, expressed significant frustration over the decision, while a series of parliamentary committees have launched inquiries into the circumstances surrounding the case's abandonment. The charges, brought under the now-repealed 1911 Official Secrets Act against former parliamentary researcher Christopher Cash and teacher Christopher Berry, were dropped in September, just a month before the trial was due to commence. The Crown Prosecution Service (CPS) stated that it withdrew the charges because the government failed to provide sufficient evidence demonstrating that China represented a “threat to the national security of the UK,” a specific definition required by the espionage legislation.

Chairs of the Home Affairs, Foreign Affairs, Justice, and National Security committees jointly wrote to Parkinson, demanding a fuller explanation for the dropping of charges. They specifically questioned what steps Parkinson took to inform ministers that the case was at risk due to a change in case law, which necessitated the designation of China as a national security threat. Further inquiries were made into whether a key government witness, Deputy National Security Adviser Matthew Collins, was warned about the potential insufficiency of his evidence and if alternative sources of evidence regarding China's threat level were considered. Parkinson is widely expected to be summoned before MPs to detail the CPS's decision-making process.

MI5’s director general, Ken McCallum, openly conveyed his frustration with the decision, emphasizing that he would “never back off from confronting threats to the UK.” McCallum revealed that security services had recently disrupted a separate threat from Beijing, although unrelated to parliament. He underscored that Chinese state actors pose a national security threat “every day” and noted a 35% increase in individuals under investigation by MI5 for state-based threats from all countries in the past year, highlighting the growing scale of the challenge.

Prime Minister Keir Starmer reiterated his disappointment over the case's collapse and firmly denied any government involvement in the decision to drop the charges. Downing Street clarified that it would have been