The semi-secret Special Immigration Appeals Commission (SIAC) decided today that the revocation of her citizenship in 2019 was lawful.

Mr Justice Jay told the court that her appeal had been fully dismissed.

Ms Begum was 15 when she travelled with two school friends to Syria in 2015. She had three children, all of whom have died, after marrying an Islamic State fighter.

Now 23, she lives in the al-Roj camp in north-east Syria, which she says is “worse than prison”.

In 2019, then-Home Secretary Sajid Javid stripped her of her British citizenship. SIAC ruled that the decision, taken after ministers were given national security advice about the threat she posed to the UK, had been lawful.

Devyani Prabhat, professor of law at the University of Bristol Law School, said: “Today’s decision about Ms Begum losing her appeals is far from the end of the legal issues, as this will be followed by appeals and other proceedings by her team.

“It only highlights the complexity of the issues and is one step in a long journey in Begum’s cancellation of citizenship proceedings. The Special Immigration Appeals Commission has decided today that the cancellation of her citizenship was lawful, which means it was within the decision making powers of the Secretary of State as per Section 40 of British Nationality Act 1981.

“There is wide discretion given to the Secretary of State in this section for national security so it is quite difficult to challenge this, especially when there is evidence which is secret or not publicly available.”