The head of MI5 has warned of a significant rise in the threat posed by rightwing extremists in the United Kingdom, particularly those holding anti-immigration and anti-Muslim views who are increasingly moving towards planning terrorist attacks. Ken McCallum, MI5’s director general, highlighted this shift from extremist rhetoric to violent intent as the most notable trend in the agency’s recent work, contributing to an overall increase in the UK terror threat level.

McCallum detailed that attacks could target immigration centres, asylum hotels, mosques, and other venues associated with migrants and Muslim communities. He cited several aggressive anti-migrant protests this autumn by the far-right group Patriot Platform in locations such as Portsmouth and Dover, while also noting that racially and religiously motivated offences are at record highs. He expressed particular concern about young people gravitating towards extreme rightwing terrorism, mentioning an ongoing investigation into a radicalised 13-year-old in the UK and recalling the sentencing of a 16-year-old from Inverclyde who was convicted for planning a mass attack on a Muslim centre in Greenock.

Beyond rightwing extremism, McCallum described an increasingly complex security environment marked by a surge in hostile activity from states including Iran, Russia, and China. Iran was reported to have intensified its efforts to carry out violent plots on British soil, with ambitions to target more heavily defended military sites such as RAF Fairford airbase in Gloucestershire. Recent arrests in the UK related to Iran’s activities exceed 50 within the past year, many linked to threats against Jewish communities, including planned attacks on synagogues and associated targets. Two men from Liverpool and Salford were recently charged with attempting to manufacture a chlorine bomb targeting Jewish sites in Manchester, allegedly under direction from Iranian handlers.

Russia remained identified as the foremost aggressor, with Moscow continuing to conduct cyber operations, assassination plots, and disinformation campaigns aimed at destabilising the UK and Western democracies. McCallum reaffirmed Russia's role in interfering with the 2016 Brexit referendum and described Moscow’s actions as part of a broader effort to intimidate and divide. Meanwhile, MI5 also faces espionage challenges from China, adding to the range of state-level threats.

Amid these challenges, McCallum emphasized a broader rise in politically, religiously, and community-targeted violence. He cited the killing of former minister and Reform UK spokesperson Ann Widdecombe by a suspected extreme left-wing attacker as indicative of this troubling trend.

Underlining the evolving threat landscape, McCallum warned about the increasing potential for artificial intelligence (AI) to be exploited by hostile states and terrorist groups. He highlighted risks such as AI enhancing cyber-attacks, producing targeted propaganda, and even contributing to the development of novel bioweapons. In response, MI5 is establishing a new AI Threat Assessment Centre aimed at distinguishing fact from fiction and better preparing for these emerging dangers.

Overall, McCallum characterized the current period as a “new era of national security,” with threats from foreign states and extremist groups taking on renewed urgency. He urged greater societal resilience in the face of this multifaceted threat environment, emphasizing the ongoing importance of protecting democratic institutions, representatives, and values.