Kathleen Unsworth, R (on the application of) v Carlisle Magistrates Court & Anor.

Permission for judicial review should be granted where the grounds cross the threshold of arguability and have a realistic prospect of success. At the permission stage, the court should identify whether the claim merits investigation at a substantive hearing on the evidence and legal arguments. The court need not resolve disputed facts or determine the merits, and the absence of a decisive preliminary objection does not prevent permission being granted. Where intelligence relied on by the defendants has been redacted, the court may direct a public interest immunity hearing to address disclosure and evidential issues.

The claimant, a vulnerable 99-year-old householder with dementia, challenged the obtaining, maintenance and execution of a drugs-related search warrant concerning alleged cannabis cultivation in her home. The claim raised issues about the application to and decision of the magistrate, subsequent police conduct, the use of an access-code, the involvement of social workers, and compliance with statutory, human-rights, common-law and Code of Practice requirements.

Permission had previously been refused on the papers. On an oral reconsideration, the Administrative Court considered whether the grounds were arguable with a realistic prospect of success and whether the issues required investigation at a full hearing.

1. Permission granted. The grounds crossed the threshold of arguability and had a realistic prospect of success. The claim therefore merited investigation at a full hearing with the relevant evidence and legal submissions.
2. The court did not determine the disputed facts or the substantive legality of the warrant or its execution. The evidence required further gathering and the legal submissions required fuller development. The court found no preliminary point which disposed of the claim at the permission stage.
3. The issues potentially included what occurred before the warrant application, the obtaining and granting of the warrant, events after it was obtained, and the manner of execution. The magistrate might also be able to provide relevant material.
4. Because the intelligence relied on by the defendants had been redacted, a public interest immunity hearing was directed. The court made consequential directions for detailed grounds, witness statements, the PII hearing and, subject to variation, the substantive hearing. Costs were in the case.

Permission had been refused on the papers. On reconsideration at an oral hearing, the Administrative Court granted permission for judicial review and gave directions for the further proceedings.