Record number of terrorists now locked up in Britain - the majority convicted for Islamist extremism

Published: 09:15 EDT, 8 October 2026 | Updated: 09:36 EDT, 8 October 2026 A record number of convicted terrorists are now locked up in Britain, with the majority holding Islamist-extremist views, new data shows.There were 275 people in prison for terror offences at the end of June, the highest number since records began in 2010, when there were 126.Data released by the Home Office showed the number is up seven per cent since last year, and has surpassed the previous peak of 273 recorded at the end of March.The increase comes after the proscription of Palestine Action, the first direct action protest group to be banned under the Terrorism Act, which has led to thousands of arrests. According to the data, 57 per cent of those in jail for terrorism held Islamist-extremist views while 29 per cent had extreme right-wing beliefs.Around 38 individuals (14 per cent) were classed as holding 'other' ideologies.Separate data from the Ministry of Justice revealed that, of the 34 people in that category in March, four were classed as 'far-left or anarchist', eight held multiple ideologies, 10 had 'no ideology' and 12 were designated as 'other'.The Home Office figures also revealed that more than half of all terrorism arrests in Britain since the 9/11 attacks have come in the past year. A record number of people are behind bars in Britain for terrorism offences. Pictured: anti-terror police raid a property in Eastbourne More than half of all terror arrests in Britain since 9/11 have happened in the last year since the proscription of Palestine Action. Pictured: a protester is carried away by police Tory grandee Sir Jacob Rees-Mogg spoke out against the proscription of Palestine Action earlier this week, calling it an 'overzealous' expansion of laws designed to prevent violenceOf the 7,385 people who have been arrested for suspected activity since the 2001 attacks, 3,867 happened in the year to June.The vast majority of those (94 per cent) were linked to support for Palestine Action, which was proscribed in July last year.In the previous 12-month period, prior to the ban coming into force, some 234 terror arrests were made.Members or supporters of Palestine Action face up to 14 years in prison under the ban brought in by then-home secretary Yvette Cooper. The ban is subject to an ongoing legal challenge from the group's co-founder Huda Ammori.In February, High Court judges ruled the proscription was unlawful. The Home Office challenged the decision and saw it overturned in the Court of Appeal after judges found the ban on the organisation as a terror group was a 'justified and proportionate' interference on freedom of expression rights.Ms Ammori has since made a bid to take her case to the UK's highest court and vowed to go to the European Court of Human Rights if necessary. Supreme Court judges are due to hear the challenge against the ban next month.The decision to ban the group has come under criticism from both sides of the political fence.Earlier this week, Tory grandee Sir Jacob Rees-Mogg told American journalist Tucker Carlson that banning the group had 'made the government look stupid'.'We have historically protected freedom of speech and we are now attacking freedom of speech, and I'm deeply concerned about that,' he said.'I'm very against banning things. I would never ban things. I'm not in favour of the way free speech is being policed in this country.'I happen to think this has been completely stupid. They banned [Palestine Action] and then they arrested elderly people who belong to it, which has made the government look stupid.'I mean, the reason this matters is that governments have power to stop terrorist organisations. Quite right, they need to have that power. But what they've done with Palestine Action is confuse the people who support it politically with the people who are bad people who want acts of violence.'And therefore they've arrested elderly people who, to my mind, are very silly people, but nonetheless are entitled to their view. I don't think the arrest of people for supporting a political view is right. I do think it is reasonable to arrest people who propose and prepare acts of terrorism.'Some 52 terrorists were freed from jail in the past year. Terrorists are not eligible to be freed early from jail as part of the Government's bid to tackle overcrowding. They still have to serve two-thirds of their sentence behind bars and face the Parole Board before walking free.