On 16 June 2016, Labour MP Jo Cox was shot and stabbed to death outside her constituency surgery in Birstall, West Yorkshire, by a far-right extremist. She was 41, a mother of two young children, and had been an MP for just over a year. The murder, which occurred a week before the EU referendum, sent shockwaves through the country and sparked a national conversation about political hatred and division. A decade on, her sister Kim Leadbeater, now the Labour MP for Spen Valley, says the promised ‘kinder, gentler politics’ has not materialised — and that things have actually got worse.
Jo Cox was killed by Thomas Mair, a man described in court as an English nationalist. He shouted “Britain first” during the attack. The murder came at a time of intense political polarisation, with the Brexit campaign in full swing. Just hours before Cox’s death, Nigel Farage had unveiled the “breaking point” poster, which showed Syrian refugees lining up at a border. In the immediate aftermath, both Labour leader Jeremy Corbyn and then Prime Minister David Cameron called for a more tolerant politics. Cameron urged people to “drive out” intolerance, and Corbyn spoke of a “kinder and gentler politics”.
“10 years after Jo Cox's murder, an explainer on the killing, its political impact, and why UK politics is more divided.”
But according to Leadbeater, that consensus was short-lived. “Sadly and regrettably, over the last decade things are worse,” she told the Guardian in 2026. The years since have seen an increase in far-right activity, protests outside asylum hotels, and the 2021 murder of Conservative MP Sir David Amess by an Islamic State sympathiser. A teacher in Cox’s old constituency was forced into hiding after showing a cartoon of the Prophet Mohammed. Political scientist Rob Ford of the University of Manchester says Brexit “accelerated rather than created” the deeper forces driving populism. “There’s no centrist position on prejudice,” he argued.
For UK readers, the legacy of Jo Cox’s murder is a stark reminder of how political hatred can turn violent — and how the promise of a more respectful politics has been undermined. The case highlights the persistent threat of extremism, both far-right and Islamist, and the way in which immigration and identity have become flashpoints. Ten years on, St George’s flags and anti-migration protests have become recurring features of the political landscape. Her sister continues to advocate for common ground, but warns that people are being “pushed towards the extremes”.
Key questions answered
Q: Who was Jo Cox and why was she killed? Jo Cox was the Labour MP for Batley and Spen, elected in 2015. She was murdered on 16 June 2016 by Thomas Mair, a far-right English nationalist with links to neo-Nazi groups. Her killing was politically motivated: Mair shouted “Britain first” and targeted her because of her pro-immigration and pro-European views.
Q: What was the ‘breaking point’ poster and how is it connected to her murder? The “breaking point” poster was unveiled by Nigel Farage on the same day Cox was killed. It showed a long line of Syrian refugees under the slogan “We must break point of the EU”. Critics said it stoked anti-immigrant sentiment. The timing linked the murder to the toxic atmosphere of the Brexit campaign.
Q: How has political division changed in the UK over the past 10 years? According to Kim Leadbeater and experts, division has deepened. Far-right protests, attacks on MPs, and constant battles over immigration have become more common. The murder of Sir David Amess in 2021 showed that MPs remain vulnerable. The politics of “kinder, gentler” has given way to what some describe as an even more polarised climate.
What happens next Kim Leadbeater continues to serve as MP for Spen Valley and to campaign against extremism. The 10th anniversary has prompted reflection on whether the UK can reduce political violence and hatred. But with no sign of the underlying forces — Brexit fallout, immigration debates, and social media echo chambers — fading, the question of how to build common ground remains open and urgent.