Introduction

Onuzi v Secretary of State for the Home Department [2025] EWCA Civ 1337, Court of Appeal (judgement handed down 21 October 2025), is yet another case where the lack of detail in the British Nationality Act 1981 (1981 Act) as to how tribunals should consider appeals in citizenship deprivation cases has led to further consideration by Senior Courts. The broad principles for such consideration have been set out in the Supreme Court judgment in R(Begum) v Special Immigration Appeals Commission [2021] UKSC 7, [2021] AC 765. However, in different scenarios, the correct application of those principles continues to be explored.

Onuzi
The case concerned an appeal from the Upper Tribunal where the Secretary of State, using a power conferred by s. 40(3) of the 1981 Act, had made a decision to deprive Mr Onuzi of his British citizenship (acquired by naturalisation) on the grounds that it had been obtained by fraud. Mr Onuzi had claimed asylum using a false identity, among other things, claiming to be from Kosovo rather than Albania. Thereafter, although his asylum claim had been refused, he was granted indefinite leave to remain on account of prior Home Office errors in its handling of his case. While still maintaining his false identity, he applied for and obtained British citizenship, proceeding thereafter to build a life for himself in the UK over many years.

Having uncovered his true identity, the Secretary of State made her deprivation decision. Following that decision, on appeal to the First-tier Tribunal, Mr Onuzi succeeded in arguing that his British citizenship had not been obtained by means of fraud (it being predicated on the grant of indefinite leave itself granted to overreach Home Office error) and that there was no basis to deprive him of citizenship. However, the Secretary of State appealed and the Upper Tribunal found an error of law in the First-tier Tribunal’s approach, going on to remake the decision and to dismiss Mr Onuzi’s appeal.

Thereafter, the Court of Appeal granted Mr Onuzi permission to appeal on the basis that his case afforded the Court an opportunity to consider the proper test to be applied on appeal to the First-tier Tribunal. However, a short time later, the Court of Appeal handed down judgement in Chaudhry v Secretary of State for the Home Department [2025] EWCA Civ 16, [2025] KB 395, holding in that case that a tribunal hearing a deprivation appeal had a fact-finding jurisdiction as regards whether there had been fraud but could only review the Secretary of State’s decision that citizenship had been acquired by means of fraud on public law principles. Therefore, the Court of Appeal was bound by that decision when it came to hear Mr Onuzi’s case. Before the Court of Appeal Mr Onuzi had set out a developed case as to why the Court had been wrong in Chaudhry to find that the Secretary of State’s decision that citizenship had been acquired by means of fraud could only be reviwed on public law principles. However, by the time the appeal was heard, it was accepted that the decision in Chaudhry was binding on this point at this level in the hierarchy of judicial consideration.

Given the developments in the law as a result of Chaudhry, as well as the subsequent judgment of the Supreme Court in U3 v Secretary of State for the Home Department [2025] UKSC 19, [2025] 2 WLR 1041 (which re-surveyed the jurisdiction of tribunals in citizenship deprivation appeals), Mr Onuzi took the opportunity to reformulate his case within the grounds on which he had been given permission to appeal. In substance, he argued that when the Secretary of State considers whether British citizenship has been acquired by means of (subsequently discovered) fraud, she should look back to consider what she might have done had she known of the fraud at the time she was considering whether to grant the citizenship application.

Argument
It was submitted that in so doing, the Secretary of State must consider what it is likely that she would have done under British nationality law and policy as it stood at that time. In Mr Onuzi’s case, the applicable naturalisation policy as to when an applicant was of good character was both evaluative in nature and flexible in application. It was not the case that had the fraud been known, refusal was inevitable. It was argued that on appeal, on the basis that public law principles apply, the First-tier Tribunal should review whether the Secretary of State had taken this approach or whether she had fallen into error.

Outcome
In giving judgment, the Court of Appeal held that no error arose in the Upper Tribunal dismissal of Mr Onuzi’s appeal. It held that there was nothing in the decision-making history to break the causative link between the Appellant’s fraud and the grant of citizenship. Against that backcloth, it found no public law error in the Secretary of State’s deprivation decision that, had the truth been known, Mr Onuzi would have been refused British citizenship on the grounds that he was not of good character. In so doing, the Court did not give express consideration as to how a tribunal ought to proceed in applying public law principles when determining an appeal against a deprivation decision made on grounds that citizenship had been obtained by fraud. Such issues remain to be explored.

Adrian Berry KC, Christopher McWatters, and Tomor Bhaja acted for Mr Onuzi, instructed by Rajni Chodha of Duncan Lewis Solicitors.