Shamima Begum loses final bid to challenge removal of British citizenship as Supreme Court rules Isis bride cannot appeal again

Last year, the 24-year-old's claim to appeal against the decision to revoke her citizenship on national security grounds was rejected at the Special Immigration Appeals Commission (SIAC).

Her citizenship was invalidated in 2015 after she was discovered in a Syrian refugee camp after she joined the Islamic State group as a 15-year-old.

Justices at the UK's highest court said Begum could not appeal again after she lost a Court of Appeal bid in February.

The three justices said that there was no arguable challenge to the Court of Appeal's decision.

In a statement, her legal team said: "It is a matter of the gravest concern that British women and children have been arbitrarily imprisoned in a Syrian camp for five years, all detained indefinitely without any prospect of a trial.

"All other countries in the UK's position have intervened and achieved the return of their citizens and their children.

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"Two weeks ago the US State Department once again addressed the responsibility of countries to repatriate their nationals from the camps in north east Syria. The UK is now alone in its position.

"The UK courts have for five years offered no exit route despite the critical humanitarian crisis in the camps.

"Instead the Supreme Court has today left resolution to another court, this time in Strasbourg.

"Whilst on behalf of Ms Begum we, her lawyers, will take every possible legal step including to petition the European Court of Human Rights, this is an issue that can and should as the US urges, be resolved for all nationals by their own countries."

Begum's lawyer told the SIAC hearing that her client had been "influenced" along with her friends by a "determined and effective" Isis "propaganda machine".

The appeal court accepted that Begum "may well have been influenced and manipulated by others", but added she could "still have made a calculated decision to travel to Syria".

She is one of around 900 people who are estimated to have travelled from Britain to Syria and Iraq to join Isis.