Britain risks creating 'new Guantanamo' in Syria, warns rights group

The director of Reprieve, Maya Foa, the who has been a key figure in assisting Begum’s case, said the judgment left the 21-year-old in a legal limbo, unable to return to the UK or mount an effective challenge to the decision remotely.

Foa said the supreme court had decided that Begum could in theory still challenge the decision to take away her citizenship if she could find a way of instructing her lawyers.

"The court has said she can appeal [against] the citizenship decision, but they do not say how it can be done," Foa said.

"It leaves her in the hands of the British government, which is unwilling to assist," she said. "That is less of a policy and more of an abdication of responsibility – unless the policy is to create a new Guantánamo in Syria."

Begum has reportedly been notified of the court judgment, but little of her personal story was mentioned during the case.

Advocates of reinstating her citizenship argue that she was a minor and was a victim of trafficking, and unable to leave Syria after her arrival to join the Islamic State in 2015.

Her legal team has yet to decide the next step, which may include appealing to the European Court of Human Rights.

Five judges at the Supreme Court gave a unanimous decision in the case of Begum, whose legal battles have come to be seen as a test of how Britain treat nationals who joined the jihadists.

They found her right to a fair hearing did not override considerations such as public safety, and that the decision to block her return should remain until she can participate "without the safety of the public being compromised". 

"That is not a perfect solution, as it is not known how long it may be before that is possible," the head of the Supreme Court, judge Robert Reed, said in a written statement.

"But there is no perfect solution to a dilemma of the present kind."

Now 21, Begum left her home in east London at age 15 to travel with two school friends, and married an IS fighter.

Britain's then-Home Secretary Sajid Javid revoked her citizenship in 2019 on national security grounds following an outcry from right-wing newspapers.