Britain’s domestic intelligence agency, MI5, has issued a fresh warning to Members of Parliament, alerting them to active espionage efforts by agents linked to China, Russia, and Iran. The agency says these foreign operatives are working to infiltrate and influence the UK’s democratic system.

In new security guidance shared with lawmakers on Monday night, MI5 cautioned that spies may attempt to gather information through methods such as blackmail, phishing scams, or by cultivating long-term personal relationships with MPs and their staff. The agency also advised politicians to stay vigilant while traveling abroad, communicating online, or accepting political donations—common avenues for potential foreign interference.

According to MI5, the UK remains a target for “long-term strategic espionage and interference” from these three states, each employing different tactics to pursue their objectives.

“When foreign states steal sensitive UK information or manipulate our democratic processes, the damage goes far beyond the immediate,” said MI5 Director General Ken McCallum. “They undermine the very foundations of our sovereignty and weaken our ability to protect our national interests.”

The guidance cited previous instances of political interference, including the high-profile case of Christine Lee. In 2022, MI5 warned Parliament that the London-based lawyer was allegedly involved in political interference on behalf of the Chinese Communist Party. The agency claimed Lee had facilitated financial donations to British politicians using funds from individuals in Hong Kong and China.

Lee denied the allegations and later sued MI5, arguing that the warning was politically motivated and infringed on her human rights. She lost the case in court last year.

The new MI5 warning follows the collapse of a recent case involving two British men accused of spying for Beijing. Prosecutors dropped the charges after the UK government declined to formally label China as an “enemy” or a national security threat—raising fresh questions about how Britain defines and responds to foreign espionage in an increasingly tense global environment.