After being discovered in a Syrian refugee camp in 2019, Begum, 24, who had traveled to Syria with two pals when she was fifteen, had her citizenship revoked on the grounds of national security.

Begum wed an IS fighter in Syria, where she gave birth to three children who all passed away at a young age.

Begum, an east London native, has maintained that the decision to withdraw her citizenship was illegal, partly due to British authorities' improper assessment of whether or not she was a victim of human trafficking.

But that argument was thrown out by both a specialist tribunal in February 2023 and then the Court of Appeal last February.

On Wednesday, justices at the UK's highest court said Begum could not appeal again.

In their decision, Lords Reed, Hodge and Lloyd-Jones found her proposed appeal grounds "do not raise an arguable point of law".

The three justices said there was no arguable challenge to the Court of Appeal's decision, including on whether Begum should have been able to make representations to the then home secretary before she was stripped of her citizenship.

Dismissing her Court of Appeal challenge in February, the Lady Chief Justice Baroness Carr, said: "It could be argued the decision in Ms Begum's case was harsh.

"It could also be argued that Ms Begum is the author of her own misfortune, but it is not for this court to agree or disagree with either point of view.

In March, Court of Appeal judges rejected Begum's initial bid to take her case to the Supreme Court.