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Refusals of naturalisation on good character grounds can only be challenged by irrationality


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In a colourfully-worded and expressive judgment, the High Court has found that challenges to the Home Secretary’s decision to refuse citizenship naturalisation applications can only be challenged on grounds of irrationality. The judgment is R (Sandy) v Secretary of State for the Home Department [2023] EWHC 640 (Admin).

The facts

Kanja Sandy was born in Sierra Leone in 1972. He had aligned himself with Johnny Paul Koroma, who seized power during a coup in 1997, acting as his aide-de-camp. Personnel from the Koroma regime were known to have committed numerous atrocities amounting to war crimes.

In 2001, Mr Sandy left Sierra Leone. He obtained asylum in the UK on 13 November 2001 on grounds that his voluntary embrace of martial service meant that if he were to return to Sierra Leone, there was a reasonable likelihood that he would face persecution. He is now married with children and works as a nurse in an NHS hospital. It was undisputed that his conduct since his arrival in the UK has been irreproachable.

Mr Sandy made his first application for naturalisation in 2011. It was refused on good character grounds, but he was granted indefinite leave to remain. His second application was again refused on good character grounds in 2019. His third application, which was the subject of the present judicial review challenge, was refused on 8 April 2022.

In the decision, reference was made to his actions in Sierra Leonne, specifically that he was “responsible for aiding the war crime of intentionally directing attacks involved in a peacekeeping mission”. Whilst recognising the positive aspects of his life since arriving in the UK, it was considered that there was no “compelling evidence to show strong countervailing circumstances” in light of his past conduct.

The judicial review

One of the requirements for a grant of a certificate of naturalisation is that the applicant “is of good character”. Section 6(1) of the British Nationality Act 1981 provides that where the Secretary of State is satisfied that the applicant fits this requirement, “he may, if he thinks fit”, grant a certificate of naturalisation.

Permission was granted on one ground, which can be broken into three sub-grounds, namely that the decision-maker erred in law by failing to consider: (a) the defences available to Mr Sandy in his commission of war crimes; (b) the degree to which he distanced himself from his past membership and associations; and (C) the degree of his involvement in the relevant activities.

Standard of review

The challenge in this case was to the Secretary of State’s finding that the claimant was not of good character. Mostyn J – perhaps motivated by his imminent retirement from the High Court bench – decided to grasp the nettle and address one of the more controversial issues in administrative law head on, namely whether the standard of review of the Secretary of State’s finding was proportionality or irrationality.

In general, proportionality review entails a greater degree of scrutiny than rationality review. There is a balancing of factors and (to an extent) subjective apportionment of weight (see especially analyses in respect of interference with Convention rights). In contrast, the classic formulation of irrationality describes it as involving a decision being “so outrageous in its defiance of logic or of accepted moral standards that no sensible person who had applied his mind to the question to be decided could have arrived at it”.

Some recent Supreme Court decisions (such as Pham v SSHD [2015] UKSC 19) have suggested that the distinction is more illusory than real because English law has expanded rationality to incorporate elements of proportionality, by deploying a ‘sliding scale’ by which the cogency of justification required is linked to the perceived importance of the subject matter.

In this case, Mostyn J first considered the nature of the Secretary of State’s assessment that whether someone is of good character was a concrete fact. He considered that such an assessment was not; rather, it requires a formulation of a valued judgment, an evaluation. In this regard, previous judgments have noted that, where a court evaluates the evidence, it is very difficult to be challenged on appellate review. This principle applies with greater force to a court’s review of a decision-maker’s evaluation.

There were several other factors pointing in favour of a conclusion that the standard of review should be the narrower bounds of Wednesbury irrationality, rather than proportionality. First, the power to grant a certificate of naturalisation was a longstanding statutory power as opposed to, for example, a prerogative power, entrusted to the Secretary of State in a longstanding expression of democratic will. Secondly, the good character requirement is not something that is objectively verifiable and carries a high subjective content. Finally, a person aggrieved by the Secretary of State’s exercise of the power is not entitled to any right of appeal.

Against proportionality

The above was sufficient to dispose of the central issue on the standard of review, but Mostyn J proceeded to express his views on the (de)merits of proportionality review in judicial review.

In his characteristically colourful language, he said:

“There is no doubt that in the world of judicial review proportionality has advanced like a cuckoo, occupying the common law nest of traditional assessment, laying its continental eggs in it, and ejecting its home-incubated Wednesbury hatchlings…

The problem with allowing the advance of the cuckoo is that (to mix metaphors) it opens the door to a review of the merits and, however much the contrary may be protested, the result is that the judicial reviewer steps into the shoes of the decision-maker. It is for this reason that a line has been drawn…”

Addressing the grounds advanced by Mr Sandy

Having set out the standard of review as irrationality, the Judge made short shrift of the grounds advanced.

As to potential war crime defences (a), it was Mr Sandy’s case when applying for asylum that his risk of persecution arose from his voluntary embrace of martial service. In circumstances where he did not otherwise raise defences by way of evidence, there was no duty on the Secretary of State to treat him as having advanced them.

The lack of direct involvement in war crimes (b) (even if accepted) was also no impediment to a rational finding that the good character requirement was not satisfied, on the basis of indirect involvement. In any event, Mr Sandy was indisputably associated with organisations guilty of perpetuating war crimes, and this could undoubtedly support the aforementioned finding.

As to the degree to which he has now sought to distance himself (c), this had clearly been taken into account by the decision-maker.

Again, Mostyn J went further and gave his view that the first and third points above were  “totally without merit”. In this regard, he would not have himself granted permission to apply for judicial review. The claim was therefore dismissed.


On one view, the central finding on the standard of review was not particularly surprising. The standard of review was not dissimilar to that applied by, for example, by the Court of Appeal recently in R(Amin) v SSHD [2022] EWCA Civ 439.

What is significant is Mostyn J’s willingness to express scepticism of a proportionality review, the rationale behind which arguably demonstrates that he is also sceptical of sliding scale (a.k.a variable intensity) irrationality review, as enunciated in the Supreme Court cases like Pham. It is unlikely that any significant number of judges would be willing to articulate such scepticism in terms similar to Mostyn J, so this might not amount to more than the candid view of a retiring judge.

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Gabriel Tan

Gabriel Tan

Gabriel Tan is an incoming Bachelor of Civil Law candidate at the University of Oxford and former public law caseworker at Wilson Solicitors