Halton Borough Council, R (on the application of) v Secretary of State for Levelling Up, Housing and Communities

At the permission stage of a judicial review, the court decides only whether the proposed grounds are arguable. It does not determine the substantive merits. Where a costs decision under planning inquiry guidance turns on alleged unreasonable conduct, questions concerning the timing of withdrawal, the distinction between procedural and substantive conduct, and the adequacy of reasoning may properly remain open for substantive determination. Alleged failures of due diligence concerning expert evidence can raise arguable public law issues, particularly where an expert’s evidence changes materially under cross-examination.

These judicial review proceedings concerned the Secretary of State’s decisions requiring Halton Borough Council to pay the costs of the Health and Safety Executive and Viridor Energy Ltd in a called-in planning inquiry. The costs decisions treated the Council’s withdrawal of support for its planning application as unreasonable conduct, partly because its expert evidence had not been capable of standing up to scrutiny.

The proceedings followed an earlier judgment of HHJ Stephen Davies, sitting as a Deputy High Court Judge, reported at [2023] EWHC 293 (Admin). One ground already had permission, one had been abandoned, and four further grounds were pursued at this hearing. The central issue was whether those grounds, concerning the Guidance, expert due diligence, public law reasonableness and the adequacy of the decision letters, were arguable.

1. Permission granted in relation to the renewed grounds. The court held that the five interlinked grounds pursued at the hearing crossed the threshold of arguability. The Secretary of State had identified an arguable defence, but had not defeated the claim at the permission stage. The court therefore decided only that the claim was arguable, not that any ground would ultimately succeed.
2. There was plainly good reason for the Council to withdraw its support after its expert’s concessions under cross-examination, since withdrawal avoided further costs. The arguable issue was whether there had been good reason not to withdraw earlier, and whether the Guidance’s reference to withdrawal without good reason could encompass belated timing.
3. The court identified arguable questions concerning the Guidance’s distinction between conduct relating to the substance of a case and procedural conduct. Those questions included whether withdrawal prompted by expert evidence about planning merits was substantive, procedural, or a case-specific application of the Guidance, and whether the costs decisions created an undesirable incentive to maintain an unsustainable merits position.
4. The alleged failure of due diligence concerning expert evidence also raised arguable public law questions. The relevant considerations included the preparation of expert evidence as a team exercise, whether the circumstances required the party to interrogate its expert, and whether the expert’s position was plainly wrong or ought to have been obvious. The court referred to Ridgeland Properties Ltd v Bristol City Council [2011] EWCA Civ 649 and R (DPP) v Aylesbury Crown Court [2017] EWHC 2987 (Admin) [2018] 4 WLR 30.
5. The substantive hearing was directed to be listed for one day, if possible before Fordham J, with ordinary directions for pleadings, evidence, bundles and agreed case-management documents.

This was a first-instance permission decision in judicial review proceedings. The judgment records that the proceedings followed an earlier judgment of HHJ Stephen Davies, sitting as a Deputy High Court Judge, at [2023] EWHC 293 (Admin). The court directed that the five further grounds remain open for a substantive hearing.