Three British-Bangladeshis said to have travelled to Syria to join Islamic State (Isis) have won a legal challenge against the stripping of their British citizenship after a tribunal ruled the move left them stateless. Two women who were born in the UK, known only as C3 and C4, had their British citizenship removed in November 2019 on the grounds of national security. C7, a man born in Bangladesh who became a British citizen at birth, also had his British citizenship revoked in March 2020 on the basis that he had “aligned” with Isis and was a threat to UK national security. All three appealed against the removal of their British citizenship at the Special Immigration Appeals Commission – a specialist tribunal that hears challenges to decisions to remove someone’s British citizenship on national security grounds. In a ruling, Mr Justice Chamberlain said: “C3, C4 and C7 have persuaded us that, on the dates when the decisions and the orders in their cases were made, they were not nationals of Bangladesh or any other state apart from the UK. This means that orders depriving them of their British citizenship would make them stateless.” The judge added: “The secretary of state had no power to make orders with that effect. For that reason – and that reason alone – the appeals against the decisions to make those orders succeed.” The Home Office will comply with the terms of the court’s decision, the Guardian understands. The case will probably draw comparisons with that of Shamima Begum, who fled Britain as a 15-year-old schoolgirl to join Isis in Syria and ultimately failed in her legal bid to restore her British citizenship. The UK government, in stripping her citizenship, said she was eligible for Bangladeshi citizenship, the birth country of her parents. The key difference between Begum and C3, C4 and C7 that had a bearing on the outcome of the case is the claimants’ ages. The Home Office argued that all three were dual British-Bangladeshi nationals at the time their British citizenship was removed, and so the decision did not render them stateless. But their lawyers said all three lost their Bangladeshi citizenship when they turned 21, meaning the decision did leave them stateless and was therefore unlawful. Begum was under 21. A Home Office spokesman said: “We are extremely disappointed with this judgment and the court’s decision that deprivation cannot stand in these cases. The government’s priority remains maintaining the safety and security of the UK.”