Rather than write my own detailed piece on the Supreme Court’s judgment in Pham v Secretary of State for the Home Department  UKSC 19 I’m mainly going to refer you an excellent piece by Simon Cox on the Open Societies Foundation website: Case Watch: UK Supreme Court Backs Government Rejection of Statelessness Claim.
In Pham the Supreme Court had to grapple with the issue of whether a foreign government’s denial that a person was one of their citizens was determinative of whether the person was otherwise stateless for the purpose of depriving that person of British citizenship. If the Vietnamese government’s assertion that Mr Pham was not Vietnamese was correct then Mr Pham, who had acquired British citizenship by naturalisation, could not be deprived of that British citizenship because to do so would render him stateless.
The Supreme Court did not follow the reasoning of the Court of Appeal, instead finding different reasons for allowing the Government’s appeal and remitting the case to the Special Immigration Appeals Commission (SIAC).
On reasons, Simon says:
The UK Supreme Court dismissed Pham’s appeal, upholding the remittal to SIAC. The court disagreed with SIAC for a different reason from the Court of Appeal. While the Supreme Court judges expressed themselves in different terms, all agreed that the issue of his citizenship could not be decided by reference to a Vietnamese practice or decision adopted after the British decision (para 38). The possibility that Vietnam could subsequently refuse to confirm his citizenship was not enough (para 66). If he had lost that citizenship, it could not have been before the British decision (para 101). Under the law and practice of Vietnam he was a citizen at least at that date.
Any other approach would have damaged the British government strategy of dealing with states like Vietnam. The UK authorities had contacted the Vietnamese Government before their decision, disclosing only Pham’s migration history, not his identity or the accusation of terrorism. After the British decision to strip him of citizenship, his name and other information was provided and the Vietnamese government refused to confirm he was a citizen. A ruling by the Supreme Court that this ex post facto refusal showed he had not been a citizen from some earlier date would have encouraged retroactive citizenship-stripping by states with a cavalier approach to citizenship.
The Supreme Court’s approach meant it did not decide the correctness of the Court of Appeal’s approach. That court had held that a denial of nationality which violates the rule of law does not count as a denial under the 1954 statelessness convention. Several judges clearly sympathized with the Home Office view that the language of Article 1 of the convention – “by operation of the law” – focusses on national law and its proper operation (paras 28, 65). However, the court left for another day the arguments of the Justice Initiative that the protective purpose of the statelessness conventions would be undermined by a ruling that illegal state denials of citizenship are ineffective.
The Supremes also address, at some length, some interesting legal arguments on deprivation of citizenship and EU law. Ultimately, that was not to avail Mr Pham. For a more detailed look at those issues, head to Simon’s original article.