Up to 150 terror suspects stripped of their British citizenship could attempt to return to challenge those rulings if Shamima Begum’s case stands, the security services and politicians fear.
The warning follows an unprecedented court of appeal judgement on Thursday that Begum, 20, should be allowed to return to the UK to fight the Government’s decision to revoke her British citizenship for joining Isil in Syria.
The three judges, led by Lord Justice Flaux, ruled that the Jihadi bride, who left the UK aged 15 to join Isil, could not have a “fair and effective” appeal unless she was present in person to give “proper instructions or provide evidence.”
They said this outweighed any risks to national security which could be “addressed and managed” if she returned to the UK.
Within minutes of the judgement, the Home Office said it would appeal the “very disappointing” ruling and seek a stay on her return until the appeal was complete.
The security services and senior politicians fear the estimated 150 terror suspects deprived of their citizenship and their lawyers will be studying the judgement to see if they could make similar appeals.
A Whitehall source said: “Any returning jihadi is a headache. Anybody who went out there to join Isil is problematic. We would have concerns about anybody who has been in her situation. Even if you didn’t think she was dangerous, you would have to switch resources to put her under surveillance.”
Sajid Javid, who as Home Secretary revoked Begum’s citizenship, said he was “deeply concerned.”
“First and most critically, 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 division of significant resources,” he said.
“Second, the judgement and precedents set in this case could bind the hands of the Government in managing past and future cases.
“And third, a consequence of this individual walking our streets would be that it serves as a lightning rod for both Islamist and Far Right terrorists.”
Dr Alan Mendoza, executive director of the Henry Jackson Society, said: “The deeply troubling implication of this judgment is that up to 150 terrorists are now legally entitled to enter the UK in order to appeal the decision in their case.
“The already overworked security services will have their work cut out with this potential sudden influx. This decision could have dramatic repercussions for our entire counter-terror strategy”.
Read more: The Telegraph