Defining the Threshold for Certification of Leave to Appeal in Planning Judicial Reviews: Exceptional Public Importance and Public Interest

Introduction

In Eco Advocacy CLG v An Bord Pleanála ([2025] IEHC 195), the High Court (Humphreys J.) considered an application by Eco Advocacy CLG for leave to appeal the refusal of certiorari of a strategic wind‐farm permission. Having previously secured a declaratory judgment but failed to quash the Board’s decision in Eco Advocacy v An Bord Pleanála (No. 1) ([2025] IEHC 15), the applicant advanced thirteen points, under eight broad headings, alleging questions of “exceptional public importance.” The central question was whether any of these points met the stringent statutory criteria under section 50A(7) of the Planning & Development Act 2000 (as amended) to warrant certification for appeal.

Summary of the Judgment

The Court dismissed the application for leave to appeal. It held that none of the thirteen proposed points properly:

Arise on the facts or within the pleadings;
Present a pure question of law rather than a mixed question of application;
Transcend the specific facts to create an issue of public importance, let alone exceptional importance;
Are likely to alter the outcome or address a real doubt in the law;
Serve the public interest by avoiding undue delay to a renewable energy project in the context of Ireland’s climate-emergency commitments.

The Court also refused to grant certification for hypothetical or advisory questions and emphasised the importance of finality, certainty and expedition in planning judicial reviews.

Analysis

Precedents Cited

The judgment surveys an extensive line of authority establishing the criteria for certification of leave to appeal:

Pleadings and factual matrix: Concerned Residents of Treascon and Clondoolusk [2024] IESC 28 (scope of issues within pleadings); Minister for Justice & Equality v Andrzejczak (No. 2) [2018] IEHC 11 (no abstract points).
Determinative impact: S.A. v Minister for Justice and Equality (No. 2) [2016] IEHC 646 (point must affect outcome); Rooney v Minister for Agriculture and Food [2016] IESC 1 (litigious perpetual motion).
Pure questions of law: Leech v An Bord Pleanála [2025] IEHC 157 (no factual questions); Rushe v An Bord Pleanála [2020] IEHC 429 (application versus interpretation).
Public importance: Ógalas v An Bord Pleanála [2015] IEHC 205 (resolve doubt); Nagle View Turbine Aware Group (No. 2) [2025] IEHC 3 (no appeal where no uncertainty).
Exceptional importance and public interest: Arklow Holidays Ltd v An Bord Pleanála [2007] IESC 32 (balance public interest and project delay); Cork Harbour Alliance [2022] IEHC 231 (finality in planning judicial reviews).

These and other authorities informed Humphreys J.’s rigorous application of the statutory gateway to the applicant’s 13 questions.

Legal Reasoning

The Court set out the cumulative statutory criteria for certification (section 50A(7)) as follows:

The question must properly arise: within pleadings, actually argued, pleaded in time, not a new abstract issue.
It must be a question of law: not an essentially factual issue or a mixed question of law and fact.
It must be a point of public importance: transcending the particular facts and resolving a genuine doubt in the law.
The public importance must be exceptional.
An appeal must be desirable in the public interest: taking into account legislative objectives of finality and expedition, and risks of delay to infrastructure projects.

Applying those criteria, the Court found that:

Many questions were hypothetical or advisory, lacking any factual foundation in the record.
Several merely re-argued points already decided by the CJEU (Eco Advocacy C-721/21) or the High Court, without engaging the actual reasoning.
Procedural challenges (time limits on submissions, publication of Digital Audio Recordings, costs “set-off”) were either within the Court’s case-management discretion or never actually arose on the facts.
None of the proposed questions met the threshold of exceptional public importance, and most would not alter the outcome even if resolved in the applicant’s favour.
Granting leave would prolong litigation of a renewable-energy project already delayed over five years, harming broader public interest in climate-action and energy security.

Impact

This decision reinforces several key principles for future planning judicial reviews:

High threshold for leave to appeal under section 50A(7): novelty alone is insufficient; an applicant must pinpoint a determinative, pure question of law of exceptional public importance.
Courts will resist “perpetual motion” litigation strategies that repackage already-decided questions or pursue advisory pronouncements.
Procedural case-management directions – including time allocations and publication of recordings – attract deference and will not readily be reopened on appeal.
Public interest in expedition of renewable-energy infrastructure, set against Ireland’s climate commitments, weighs heavily against delay through multiple appellate steps.

Practitioners must ensure that any application for certification is tightly focused on a genuine legal point, properly pleaded, fully argued below, and capable of changing the outcome.

Complex Concepts Simplified

Certiorari: A judicial‐review remedy quashing a decision of an administrative body (here, An Bord Pleanála).
Section 50A(7) Certification: A statutory gateway requiring that only questions of law of exceptional public importance and in the public interest proceed to appeal.
Pure Question of Law: Interpretation of legal principles, not the application of law to disputed facts.
Exceptional Public Importance: Issues that transcend the case’s facts and address substantial uncertainties in the law.
Aarhus Convention & EIA Directive: European frameworks guaranteeing public participation and environmental assessment; they do not remove all costs consequences for unsuccessful steps.
Leapfrog Appeal: A direct appeal from the High Court to the Supreme Court, requiring special leave if certification is refused.

Conclusion

Eco Advocacy CLG v An Bord Pleanála ([2025] IEHC 195) establishes a clear, structured test for leave to appeal in planning judicial reviews. It underscores that litigants must:

Formulate specific, outcome‐determinative questions that genuinely arise on the record;
Ensure these questions are pure points of legal interpretation, not re-branded factual disputes;
Demonstrate exceptional public importance – resolving doubt rather than generating it;
Show that further appeal serves, rather than frustrates, the public interest, especially in the context of climate-critical infrastructure.

This decision will guide practitioners and litigants toward more focused appellate strategies and uphold the balance between access to review and the legislative aim of finality and expedition in planning cases.