The intensity of Iranian activity against the UK has increased, with more than 20 potentially lethal plots launched last year, the head of the UK's domestic spy service MI5 said on Thursday.
In his annual address, the security agency’s director general Sir Ken McCallum said that there had been the same number of plots in the past 12 months as there had been from January 2022 to last October. A number of Iranians have been charged this year in connection with plots in the UK, including three charged last month with spying for Tehran’s foreign intelligence service.
Britain's counter-terrorism police arrested seven Iranians in May in two separate operations in connection with an imminent plot to stage an attack in the UK. Among them were five people who a former intelligence officer suggested were part of a highly trained special operations unit.
Daniel Khalife, a former soldier in the British army who escaped from prison while awaiting trial, was jailed for 14 years at the start of this year after being found guilty of spying for Iran.
Sir Ken said Iran’s “autocratic regime” is “frantically trying to silence its opponents around the world, including in the UK”. This has forced MI5 to “grow our counter-Iran effort once again”.
“MI5 has tracked more than 20 potentially lethal Iran-backed plots in just the one year since I last stood at this podium,” he said. “Behind the scenes, MI5 and our police partners continue to catch those who are reckless enough to become Iranian pawns.”
Sir Ken said that while the UK was “among the first to call out this wave of Iranian transnational aggression”, it was also part of an international effort for curb the regime. The MI5 boss said: “A few weeks ago my Australian counterpart exposed the Iranian hand behind a series of anti-Semitic attacks there, including against a cafe and a synagogue.
“Dutch colleagues revealed a failed assassination attempt in the Netherlands – and an earlier one in Spain. In a collective public response to this shared threat, 14 nations, including the UK, together condemned Iran’s efforts to kill, kidnap and harass in Europe and North America. We will continue to call out this activity, and we will confront it together.”
Sir Ken said the number of individuals being investigated for involvement in “state threat activity” had increased by 35 per cent in the last year. He said MI5 was “routinely” uncovering plots from foreign states to carry out surveillance, sabotage, arson or acts of physical violence in the UK.
The service was also grappling with the “ever-present threat” of terrorism, with a concerning number of children being drawn into investigations. In a speech at MI5’s London headquarters he said one in five of the 232 terrorism arrests last year were of someone under the age of 17.
“In 2025, a more hostile world is forcing the biggest shift in MI5’s mission since 9/11,” Sir Ken said. He warned of state-backed espionage, “including against our parliament, our universities, our critical infrastructure”. But foreign powers were also using “ugly methods” such as arson and violence.
Russia is “committed to causing havoc and destruction” around the world, he said. But he suggested the expulsion of Russian spies from embassies across Europe has left Vladimir Putin’s intelligence services relying on “disposable” proxies, often recruited online.
“In the last year we and the police have disrupted a steady stream of surveillance plots with hostile intent, aimed at individuals Russian leaders perceive as their enemies”, he said. “And we’re seeing Russia-based figures using online platforms in wider attempts, largely unsuccessful, to sow the seeds of violence, chaos and division here in the UK.”
The spy chief used his speech to say that China poses a threat “every day” to Britain’s security. Sir Ken said meddling backed by China has included cyber-espionage, stealing technology secrets and “efforts to interfere covertly in UK public life”.
Sir Ken also said MI5 has begun work on tackling the potential risk posed by rogue AI systems, and that it would be "reckless" to ignore the potential for it to cause harm. He insisted he was not "forecasting Hollywood movie scenarios", but said the intelligence agencies had to consider the risks.
He said: "MI5 has spent more than a century doing ingenious things to out-innovate our human - sometimes inhuman - adversaries. But in 2025, while contending with today's threats, we also need to scope out the next frontier: potential future risks from non-human, autonomous AI systems which may evade human oversight and control.
"Artificial intelligence may never 'mean' to cause us harm. But it would be reckless to ignore the potential for it to cause harm."
