Jihadis may try to return to Britain to fight legal battles after a court ruled Shamima Begum should be allowed to enter the UK, it has been warned.
Judges found that she could not participate in a “fair and effective appeal” because she could not communicate properly with her lawyers while in Syrian Democratic Forces (SDF) custody.
“Whilst she remains detained in the camp she cannot give effective instructions or take any meaningful part in her appeal,” said Lord Justice Flaux.
“The only way in which she can have a fair and effective appeal is to be permitted to come into the United Kingdom to pursue it.”
The case only considered Begum’s specific circumstances, but lawyers representing other detainees without access to phones or the internet could seek to use it as a legal precedent.
“Allowing her, and indeed other terrorists, back into the UK to pursue an appeal would create a national security risk that cannot be fully mitigated, even with the diversion of significant resources,” Mr Javid said.
“The judgments and precedents set in this case could bind the hands of the government in managing past and future cases.
Mr Javid claimed that if Begum reaches the UK it will be “impossible” to remove her again, and that there would be a small chance of prosecution for significant terror offences.
The government has repeatedly refused to repatriate Begum or other detained Isis members, and has been using citizenship deprivation among other legal powers to prevent them returning voluntarily.
The Home Office has already moved to block the effect of what it called a “very disappointing decision by the court”.
“We will now apply for permission to appeal this judgment, and to stay its effects pending any onward appeal,” a spokesperson said.
The Independent understands that other detainees who have had their British citizenship removed would have to apply for leave to enter the UK, and do not have valid travel documents.
Many remain in the custody of the SDF, which has called for Britain and other nations to repatriate captured foreign fighters and families.
The Court of Appeal stressed that allowing Begum to return to Britain did not mean her appeal against citizenship deprivation would succeed, and that its judgment rested “on the facts of this case” only.
Lord Justice Flaux said national security had to be considered and that overturning the removal would “set a dangerous precedent”.
The judge added that the ruling did not prevent Begum being arrested upon arrival in the UK and charged with terror offences, or made subject to a Terrorism Prevention and Investigation Measures order.
Counterterror police continue to investigate Begum but would not comment on those possibilities.
The former London schoolgirl, who left the UK for Syria aged 15, lived under Isis rule for more than three years before being found in a refugee camp last year.
She had three children with her Isis fighter husband but they all died, including a baby son born last year in the al-Hawl camp.
Sajid Javid removed her British citizenship in February 2019, as the government claimed she was entitled to Bangladeshi nationality.
But her lawyers argue that the decision made Begum stateless and exposed her to the risk of death or inhuman and degrading treatment.
The Court of Appeal ruling came days after another former London student who joined Isis in Syria reportedly died while being held in an SDF prison.
Ishak Mostefaoui, 27, was captured in March 2019 as the terrorist group lost the last scraps of territory in its self-declared “caliphate”.
In an interview with The Independent in December, Mostefaoui said he was willing to stand trial in the UK, adding: “I’ll put my hands up and do my time for that.”
Government guidance states that the home secretary can deprive citizenship for the “public good” if a person can apply for alternative nationality.
“This action may only be taken if the secretary of state (home secretary) has reasonable grounds for believing that the person is able, under the law of a country outside the United Kingdom, to become a national of that country,” says a document published last year.
“In practice, this power means the secretary of state may deprive and leave a person stateless if that person is able to acquire (or reacquire) the citizenship of another country.”
The British government removed citizenship from 139 people “for the public good” between January 2016 and December 2018.
The figure for 2019, when Begum and other alleged Isis members including Jack Letts were deprived of citizenship, has not yet been published.
A 2016 report commissioned by the government warned that removing extremists’ citizenship left them free to continue terrorist activities abroad, prevented monitoring and encouraged the “dangerous delusion that terrorism can be made into a foreign problem”.
In August, former defence minister Tobias Ellwood told The Independent the detention of thousands of jihadis and their families in Syria was creating conditions for an Isis resurgence.
“We’ll see Daesh 2.0,” he warned. “We’ll see a repeat of al-Qaeda regrouping and becoming a very real threat, and that threat won’t just pose itself in the Middle East, but also to Britain.”