Murder of Jo Cox

On 16 June 2016, Jo Cox, the Labour Party Member of Parliament for Batley and Spen, was killed while travelling to meet constituents at a routine surgery in Birstall, West Yorkshire. Thomas Alexander Mair, then 53, shot and stabbed her outside a library on Market Street, using a modified .22 hunting rifle in the attack. Cox, 41, died of her injuries shortly after being admitted to Leeds General Infirmary. Bernard Carter-Kenny, a 77-year-old retired mines rescuer, was also stabbed after intervening to help Cox; he was later awarded the George Medal for his bravery. Mair was arrested about a mile from the scene by police constables Craig Nicholls and Jonathan Wright, who were subsequently awarded the Queen's Gallantry Medal.

Mair, an unemployed gardener with documented links to British and American far-right groups including the National Front, the neo-Nazi National Vanguard, and the English Defence League, had a history of purchasing far-right publications and corresponding with extremist organisations. Investigators found Nazi regalia, far-right literature, and bomb-making information in his home, along with an internet search history covering white supremacist figures, the Ku Klux Klan, and Norwegian far-right terrorist Anders Behring Breivik. A psychiatric examination after his arrest found no evidence that his mental health impaired his responsibility for his actions, and his defence did not raise diminished responsibility at trial.

Mair's trial began at the Old Bailey on 14 November 2016. He offered no defence. Witnesses testified he shouted phrases including "This is for Britain" and "Britain first" during the attack. On 23 November 2016, a jury convicted him after about 90 minutes of deliberation on charges of murder, grievous bodily harm against Bernard Carter-Kenny, possession of a firearm with intent, and possession of a dagger. The judge stated he had no doubt Mair killed Cox to advance political, racial and ideological causes of violent white supremacism and exclusive nationalism associated with Nazism, and imposed a whole life order, meaning Mair will never be eligible for parole. The Crown Prosecution Service confirmed the conviction meant Mair is officially classified as a terrorist under UK law.

The killing prompted widespread national and international tributes, flags flown at half-mast on public buildings, and a memorial event in Trafalgar Square. Cox's death occurred a week before the 2016 EU referendum, during which official campaigns temporarily suspended activity. It was the first killing of a sitting British MP since the 1990 assassination of Ian Gow by the Provisional IRA. As of an October 2020 press report referenced in coverage, West Yorkshire Police had been unable to establish how Mair acquired the firearm used in the attack, describing the matter as unresolved but subject to review if new information emerged.