"17. …PII is a ground for refusing to disclose a document which is relevant and material to the determination of the issues. A successful claim for PII renders a document immune from disclosure, depriving both the Court and the parties of relevant material, in contrast to a closed material procedure…A claim to PII can only be justified if the public interest in preserving the confidentiality of the document outweighs the public interest in the fair administration of justice. 18. The PII process involves three stages: see Al Rawi v Security Services and Others[2012] 1 AC 531 at [24]:at [24]: (a) the relevant minister must decide whether the documentary material in question is relevant to the proceedings in question, i.e. that the material should, in the absence of PII considerations, be disclosed in the normal way: see R v Chief Constable of the West Midlands, ex p. Wiley[1995] AC 275 , 280F-281C; (b) the minister must consider whether there is a real risk that it would cause serious harm to the public interest if the material were placed in the public domain; (c) the minister must balance the public interest in non-disclosure against the public interest in disclosure of the material for the purpose of doing justice in the proceedings, and, if appropriate, state in a PII certificate that it is in the public interest that the material be withheld. 19. However, it is the Court which is the ultimate decision-maker. It will consider whether the risk to the public interest that would be caused if the document were placed in the public domain can be mitigated sufficiently by other steps such that the balance of public interest favours some form of limited disclosure. These steps include all of the case management tools available to the Court, such as hearings in private, summaries, redactions, restricting the number of copies to be taken and the use of a confidentiality ring. The latter can also take various forms; for example, it may be confined to lawyers only and not include their lay client. There is no such thing as a class claim to PII any longer; the balancing exercise is undertaken by reference to the contents of the particular document in question. 20. Factors relevant to the balancing exercise include: (a) the seriousness of the claim in which disclosure is sought; (b) whether the Government is itself a party or alleged to have acted unconscionably; (c) the significance and relevance of the evidence to the case; (d) the importance of the public interest claimed; (e) the nature and degree of risk that disclosure presents; and (f) the nature of the litigation (see Al Rawi at [102] and AHK & Others v Secretary of State for the Home Department[2012] EWHC 117 (Admin) at [34] in the judgment of Ouseley J. "
"As decided in Conway v Rimmer[1968] AC 910 explained in Ex p Wiley[1995] 1 AC 274 it is then for the Court to weigh, as Lord Simon of Glaisdale put it, "the public interest which demands that the evidence be withheld…against the public interest in the administration of justice that Courts should have the fullest possible access to all relevant material", and if "the former public interest is held to outweigh the latter, the `evidence cannot in any circumstances be admitted…On the other hand, if the Court concludes that the latter public interest prevails, then the document must be disclosed unless the Government concedes the issue to which it relates…As Lord Woolf said in Ex p Wiley …even where material cannot be disclosed, it may be possible and therefore appropriate, to summarise the relevant effect of the material, to produce relevant extracts, or even to produce the material 'on a restricted basis'."
“7. I consider that the disclosure of the PII material to the Claimants, their legal representatives and the public would cause serious harm to an important public interest. In particular, I consider that disclosure would cause serious harm to the United Kingdom’s international relations, primarily (but not exclusively) with the Government of Rwanda. I further consider that damage to the United Kingdom’s international relations of the nature and extent that would be caused by disclosure of the PII material would also harm national security in light of Rwanda’s status as a valuable strategic partner to the United Kingdom across a range of issues including regional security, the maintenance of a strong coalition in support of Ukraine, and combatting the activities of criminal gangs engage in illegal immigration.”