Invited Standing and Quashing Relief: Public Authority Concession in Planning Judicial Review

Introduction

This commentary examines the Court of Appeal in Northern Ireland decision in Gordon Duff v Causeway Coast and Glens Borough Council & Alex McDonald ([2025] NICA 8), delivered on 6 February 2025 by Keegan LCJ. The dispute arose out of the grant of planning permission for an infill dwelling between 51 and 53 East Road, Drumsurn. Mr Gordon Duff, a litigant in person, challenged the lawfulness of that permission via judicial review. The Council not only conceded illegality but also explicitly invited Mr Duff to apply for certiorari to quash its decision. The key issues were (1) the appellant’s standing (“locus standi”) despite limited personal interest, (2) the appropriate remedy once illegality was conceded, and (3) whether costs should follow the event.

Summary of the Judgment

The Court of Appeal allowed Mr Duff’s appeal and reversed the High Court judge’s refusal to grant a quashing order (certiorari). It held that:

The Council’s invitation to Mr Duff to bring the judicial review established an “exceptional” basis for standing, endorsed by both this Court’s earlier decision ([2023] NICA 22) and the Privy Council ([2024] UKPC 19).
A public authority’s clear concession of illegality normally requires a quashing order unless strong countervailing reasons exist. Here, no such reasons outweighed the public interest in correcting unlawful administrative action.
The judge had erred in giving weight to the appellant’s non-participation in the planning process and lack of direct personal interest, contrary to binding precedents on environmental and planning challenges.
Costs were awarded to Mr Duff on the basis of an agreed protective costs order, recognizing the Council’s concession and ultimate success of the appellant.

Analysis

Precedents Cited

The Court of Appeal’s reasoning drew heavily on a lineage of authorities concerning standing and discretionary relief in planning judicial review:

Walton v The Scottish Ministers [2012] UKSC 44: Established a flexible, context-specific test for “person aggrieved” in planning appeals, later applied to standing in judicial review. Key principles include broad access for those who have participated in pre-decision procedures and, in some environmental cases, those who speak up in the public interest even without personal harm.
Eco-sud and others v Minister of Environment [2024] UKPC 19: Approved the Court of Appeal’s summary of Walton in Duff v Causeway Coast and Glens Borough Council [2023] NICA 22, confirming that public-spirited environmental litigants can have standing if they show a genuine concern and sufficient knowledge.
Mussington v Development Control Authority (Privy Council): Affirmed that the “person aggrieved” test aligns closely with standing for judicial review, including environmental claims, and that representation of fauna, flora or heritage can warrant standing.
Glassdrumman Road Judicial Review [2024] NICA 42: Another case where Mr Duff was granted standing and obtained quashing of planning permission for rural infill in breach of Policy CTY8.
Lancefort Ltd v An Bord Pleanála: Emphasized that locus standi should normally be decided at the leave (permission) stage of judicial review.

Legal Reasoning

The Court of Appeal’s decision rested on two intertwined strands: standing and exercise of discretion in granting certiorari.

Exceptional Standing via Council Invitation
The Court stressed that while personal interest remains relevant, the Council’s unqualified invitation to Mr Duff to bring a quashing application created an exceptional basis for standing. A public authority cannot invite review and then undermine it by raising locus standi objections. The prior ruling ([2023] NICA 22) and the Privy Council’s endorsement ([2024] UKPC 19) underscore that an applicant with genuine environmental concerns and some pre-decision engagement—or in this case, formal invitation—has sufficient interest.
Discretion to Grant Quashing Relief
Once illegality was conceded—misinterpretation of Policy CTY8, irrational reasoning on “substantial and continuously built-up frontage”—the Court applied the principle that public law remedies should correct unlawful decisions. The High Court judge had weighed the appellant’s non-participation and lack of direct harm as though they were disqualifying; the appellate court concluded these factors could not outweigh a clear concession of unlawful administrative action, mindful of the public interest in upholding planning policy integrity.
Costs
Having succeeded on both standing and substantive relief, Mr Duff was entitled to his agreed protective costs order (£5,000 plus VAT). The Court recognized that litigants in person should not be deterred from public-interest litigation when authorities admit error.

Impact

This judgment is significant for several reasons:

Reinforcement of Public-Interest Standing: It confirms that environmental or public-spirited litigants can obtain leave—and substantive relief—if the public body itself concedes unlawfulness, even if the litigant lacks personal property or amenity harm.
Clarity on Remedies: Public authorities cannot concede illegality yet successfully resist remedy; certiorari should follow clear admissions unless there are truly compelling countervailing factors.
Planning Policy Integrity: By quashing a rural infill permission improperly granted against officer advice, the Court signals to local councils that Policy CTY8’s restrictive approach to countryside development must be respected. It discourages elected members from routinely overturning professional recommendations without robust planning reasons.
Procedural Fairness: The decision underscores that third parties must not be co-opted or sidelined; councils must keep notice parties informed and cannot hedge their litigation positions.

Complex Concepts Simplified

Locus Standi (“Standing”): The threshold question in judicial review: who can sue? Beyond direct harm, courts recognize “public-spirited” challengers if they show genuine interest, expertise, or—unusually here—an invitation from the public body under challenge.
Certiorari: A remedy ordering a public body’s decision to be quashed. It corrects unlawful administrative acts. Once illegality is proved or conceded, certiorari is the usual remedy.
Policy CTY8 (PPS21): Northern Ireland’s planning policy restricts countryside development to prevent ribbon development. An “infill exception” permits building in a small gap between two existing homes only where a continuous built frontage exists. Here, both Councils and courts found that exception misapplied.
Public-Interest Litigation: Cases where individuals bring judicial review to uphold environmental or administrative law standards, even without personal property or direct harm.

Conclusion

The Court of Appeal’s decision in Duff v Causeway Coast and Glens Borough Council & McDonald crystallizes a twofold principle:

Invited standing—a public body’s express invitation to seek quashing relief establishes an exceptional basis for judicial review, reinforcing the rule of law over mere technical objections to locus standi.
Certiorari relief—once illegality is conceded, the usual and appropriate remedy is to quash the flawed decision; public-interest and administrative good order demand no less.

By reiterating the restrictive purpose of Policy CTY8 and condemning routine committee overrides of professional advice, the judgment safeguards countryside planning objectives. It also encourages transparency and responsible litigation conduct by local councils. This precedent will guide future environmental and planning challenges, ensuring that public bodies cannot admit unlawful practice yet evade the consequences.