IS bride Shamima Begum should not be allowed to return to the UK to fight a decision to strip her of British citizenship, the Supreme Court has ruled.
The decision comes six years after the then 15-year-old left with friends to join the Islamic State group.
Now aged 21, Begum was one of three schoolgirls from Bethnal Green in east London who travelled to Syria.
Her British citizenship was revoked on national security grounds shortly after she was found, nine months pregnant, in a Syrian refugee camp in February 2019.
She had already lost two children and the third died shortly after being born.
Begum challenged the Home Office's decision to remove her British citizenship and wanted to be allowed to return to the UK to pursue that appeal.
Watch: Supreme Court to consider whether she can return to UK to challenge deprivation of citizenship
Initially, the Court of Appeal said she should be allowed to return to fight the case.
However, in November, the Home Office appealed that decision at the Supreme Court, arguing that allowing her to return to the UK "would create significant national security risks" and expose the public to "an increased risk of terrorism".
Friday's Supreme Court ruling could have huge significance for the government, which has revoked the citizenship of about 150 British nationals on grounds of national security.
Begum is currently in a camp controlled by armed guards in northern Syria.
She cannot speak to her lawyers or participate in a hearing by video.
Begum spoke to Sky News days after her third baby was born in February 2019, telling correspondent John Sparks "a lot of people should have sympathy" for her as there was no evidence she had done anything dangerous.
But later that year Home Secretary Priti Patel vowed Begum would never be allowed to return to the UK.
She said there was "no way," adding "our job is to keep our country safe.
Watch: Inside camp where Shamima Begum is held