MI5 will, for the first time, publish formal guidance to members of parliament and their staff on how to protect themselves from espionage and foreign interference, according to a report by The Times UK. The move comes only days after charges were dropped against two men accused of spying for China, a decision that has angered ministers and reignited concerns about Britain’s vulnerability to hostile state activity.
The guidance, expected within weeks, will be issued through the National Protective Security Authority, MI5’s public-facing arm. It will urge parliamentarians and political aides — deemed “high-risk individuals” — to be wary of the motives of people they hire and meet, to exercise caution when connecting with individuals on social media, and to take extra care when traveling overseas. Practical measures are expected to include warnings against leaving laptops and mobile phones unattended in hotel rooms.
Although the advice is officially described as “state agnostic,” officials have made clear that the most pressing threats of interference come from China and Russia. Alongside the MI5 guidance, the National Cyber Security Centre (NCSC), part of GCHQ, is encouraging politicians to sign up for a monitoring service that can flag malicious activity on their devices and warn them if they attempt to access compromised or blacklisted websites.
The heightened security focus follows the collapse of a high-profile case involving Chris Cash, a former parliamentary researcher, and Christopher Berry, an academic. Both men were accused under the Official Secrets Act of gathering and passing information to China. Prosecutors told the court last week that the evidential threshold could no longer be met, and “not guilty” verdicts were entered on their behalf. The abrupt end to the case, which was set for trial next month, has infuriated MPs and security officials.
Commons Speaker Sir Lindsay Hoyle told The Times UK that the collapse of the prosecution would be seen as a “green light” by hostile powers. He warned: “This leaves the door open to foreign actors trying to spy on the House. This door must be closed hard.” Hoyle even suggested he may consider bringing a private prosecution against Cash and Berry.
Other MPs echoed his concerns. Alicia Kearns, the former Conservative chair of the Commons foreign affairs committee who had previously employed Cash, said the collapse of the case was “disastrous” and would embolden Britain’s adversaries. Security Minister Dan Jarvis told parliament that new powers under the recently enacted National Security Act have replaced outdated language in the Official Secrets Act, which required prosecutors to label China an “enemy” — a move seen as diplomatically sensitive given ongoing trade talks.
Meanwhile, diplomatic ties with Beijing remain complex. Business Secretary Peter Kyle visited China earlier this month to co-chair a bilateral trade commission, and speculation is growing that Prime Minister Keir Starmer could make an official visit in the coming year. The government is also seeking to restore extradition arrangements with Hong Kong, suspended in 2020 over human rights concerns.
MI5 chief Sir Ken McCallum has previously confirmed that the agency has disrupted operations linked to Beijing aimed at coercing individuals in the U.K. and influencing British politics. In 2022, MI5 issued a rare “interference alert” naming Christine Lee, a solicitor accused of acting as an agent for the Chinese Communist Party, allegations she denies.
The forthcoming MI5 guidance is expected to build on existing definitions of “high-risk individuals” developed by the intelligence community, which include those with access to or influence over sensitive political or security information. With the collapse of the Cash and Berry case still reverberating in Westminster, the new advice is intended to reassure lawmakers while sending a clear message that Britain remains alert to the threat of foreign interference.
