MI5 Chief Warns Anti-Migrant Extremism Is Tipping Into Terrorism
MI5 Director General Ken McCallum warned on 13 October 2026 that extremists holding anti-immigration opinions are increasingly likely to consider terrorist attacks against immigration centres and asylum hotels in the UK. He gave the warning as part of an annual threat update at MI5's London headquarters. The Guardian
McCallum said the shift from radicalised rightwing sentiment to violence was "the most marked trend" in MI5's caseload over the past year. He said there had been an increase in cases where extremist anti-immigration and anti-Muslim grievance tipped into terrorist intent, including planning attacks on migrants and Muslims. That trend, he said, contributed to a rise in the overall UK terror threat level.
Two cases illustrate the pattern he described. A 16-year-old from Inverclyde received a 10-year prison sentence after pleading guilty to planning mass murder by firebombing a Muslim centre in Greenock. The far-right group Patriot Platform held anti-migrant protests at Portsmouth and Dover in autumn 2026. The caseload is getting younger. McCallum said MI5 was at one point in 2026 investigating a radicalised 13-year-old in the UK.
State threats now rival terrorism. McCallum said threats from other states had quadrupled in the last decade and were running on par with MI5's counter-terrorism mission. He said Iran was trying to expand hostile activities in the UK with ambitions to target harder targets like military sites including RAF Fairford airbase. MI5's counter-Iran operation led to more than 50 arrests in the UK in the past year to October 2026.
McCallum also announced the creation of a new AI threat assessment centre to assess risks of hostile states or terrorists using AI to generate bioweapons. He warned that terrorists and other malevolent actors could soon have the capability to unleash AI-enabled drone attacks on Britain. The Telegraph Sir Ken McCallum said artificial intelligence is "supercharging" the cyber-race, warned that artificial intelligence could give terrorists new bioweapons, and said the UK is in a "new era of security." The Times
The update revises the picture McCallum has given in prior years. In October 2024, he said 75% of MI5's counter-terrorism work was focused on Islamist extremists and 25% on extreme right-wing terrorism. Reuters In October 2025, he said the UK was facing a growing threat from Russia, Iran and terrorists, and said the terrorist threat to Britain remained "huge." A year earlier, he had told an invited audience that a more hostile world is forcing the biggest shifts in MI5's mission since 9/11. McCallum said the MI5 he leads in 2026 contends with a threat landscape markedly different to 2001's. The downing of Pan Am Flight 103 in December 1988 was Britain's largest terrorist atrocity.
The broader context here is convergence. Counter-terrorism and counter-state work are no longer distinct lanes, with Tehran-linked plotting, far-right mobilisation around asylum infrastructure, and AI-enabled tactics assessed together. For practitioners, three implications stand out. First, protective security for immigration centres, asylum hotels and places of worship moves closer to the centre of counter-terrorism planning. Second, investigation thresholds will keep testing legal and safeguarding frameworks built for adults, as teenage subjects recur. Third, the AI centre points to a regulatory gap McCallum wants closed early, around dual-use biological knowledge and autonomous drones, before capability diffuses further.
