The Court of Appeal has upheld the government’s right to revoke British Passports for individuals suspected of terrorism in the case of XH & AI v Secretary of State for the Home Department  EWCA Civ 41. The case was heard in December 2016 and delivered several months later. A full copy of the judgement can be found here.
The Appellants, XH and AI both had their passports revoked in 2014 and received letters stating:
This letter is to inform you that the above passport has been cancelled and you are no longer permitted to use this document to travel to and from the United Kingdom.
There is no entitlement to a passport. The decision to issue, withdraw or refuse to issue a British passport is a matter for the Secretary of State for the Home Department (the Home Secretary). The Home Secretary considers that it is not in the public interest that you should hold a passport.
Both Appellants denied involvement in religious extremism or terror related offences. They argued that the exercise of prerogative power was invalidated because it had been impliedly abrogated by the Terrorism Prevention and Investigation Measures Act 2011 (“the TPIM Act”) and second, that their EU law rights had been breached because the cancellation of the passports was disproportionate and there were insufficient procedural safeguards. The Court of Appeal rejected their appeal in a lengthy judgement.