MI5 Warns Anti-Immigration Extremism Is Turning Toward Terror Attacks
MI5 Director General Ken McCallum warned on 13 October 2026 that extremists with anti-immigration views are increasingly likely to consider terrorist attacks against immigration centres and asylum hotels in the UK. He spoke at the annual threat update at MI5's London headquarters. MI5 is Britain's domestic security service. The Guardian
McCallum called the shift from radicalised rightwing sentiment to violence "the most marked trend" in MI5's caseload over the past year. He said there had been an increase in cases where extreme anti-immigration and anti-Muslim grievance tipped into terrorist intent, including planning attacks on migrants and Muslims. That trend, he said, helped push up the overall UK terror threat level, the official assessment of danger.
McCallum pointed to two cases. 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.
McCallum said threats from other states had quadrupled in the last decade. They were now running on par with MI5's counter-terrorism mission, the work to track and stop terrorist plots. He said Iran was trying to expand hostile activities in the UK and wanted 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 a new AI threat assessment centre to assess the risk of hostile states or terrorists using AI to generate bioweapons, biological weapons that use germs or toxins to cause harm. He warned that terrorists and other malevolent actors could soon have the capability to unleash AI-enabled drone attacks on Britain. 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 Telegraph The Times
In prior years McCallum gave a different breakdown. 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.
