Functus Officio, De Minimis Breaches and Certification under s.50A(7) of the Planning and Development Act 2000: Commentary on Morehart v An Coimisiún Pleanála [2025] IEHC 701

1. Introduction

This judgment of Farrell J in Morehart v An Coimisiún Pleanála [2025] IEHC 701 concerns an application for a certificate under s.50A(7) of the Planning and Development Act 2000 (“the PDA”) to appeal a prior High Court decision (the “principal judgment”) to the Court of Appeal. The underlying dispute arises from a planning permission granted by Monaghan County Council to the developer, Abbott Ireland (the notice party), and the refusal by An Bord Pleanála (now An Coimisiún Pleanála – “the Commission”) to grant the applicant, Mr John Morehart, leave to appeal that grant under s.37(6) PDA notwithstanding that he did not participate at first-instance before the planning authority.

The case sits at the intersection of three key planning law themes:

The limits on the Commission’s powers when it is functus officio in respect of a particular application.
The court’s discretion to refuse certiorari where there has been a technical or de minimis breach of the statutory code.
The stringent statutory test for certifying a “point of law of exceptional public importance” under s.50A(7) PDA.

Although the principal judgment dealt with the validity of the Commission’s third refusal of leave to appeal, the present (certification) judgment focuses on whether the applicant has identified a sufficiently important and determinative point of law to justify an appeal. In doing so, Farrell J clarifies:

What the court did – and did not – decide about the powers of the Commission while it is functus officio;
How the doctrine of de minimis statutory breach operates in planning judicial review; and
When a proposed “point of law” is too broad, advisory, or moot to qualify for certification under s.50A(7).

The judgment therefore establishes and reinforces important principles for planning practitioners, the Commission, and litigants seeking to challenge planning decisions by judicial review.

2. Factual and Procedural Background

2.1 The planning decision and the parties

Applicant: John Morehart, who has an interest in lands adjoining the development site.
Respondent: An Coimisiún Pleanála (successor to An Bord Pleanála; all references in the judgment are to “the Commission” pursuant to s.495(3) of the Planning and Development Act 2024).
Notice party: Abbott Ireland, the developer.

Monaghan County Council granted planning permission to Abbott Ireland on 1 February 2023, subject to conditions. Mr Morehart did not submit observations to the Council within the prescribed time. He attempted to make a late submission, but the Council refused to accept it; that refusal has not been challenged.

Because he did not participate at first-instance, he had no ordinary right of appeal to the Commission. He therefore applied under s.37(6) PDA for leave to appeal as a non-participant. Meanwhile, An Taisce independently appealed the same permission to the Commission on 28 February 2023. Mr Morehart made detailed submissions on that An Taisce appeal.

2.2 The three Commission decisions and prior judicial reviews

Crucial to the context is the sequence of the Commission’s decisions on Mr Morehart’s s.37(6) application and the parallel judicial review proceedings:

First refusal of leave (2023)
The Commission refused leave to appeal. In judicial review proceedings (2023/352 JR), it conceded that its decision was invalid. The High Court (Hyland J) granted certiorari on 5 December 2023.
Second refusal of leave (9 January 2024)
The Commission again refused leave. It similarly conceded invalidity in subsequent judicial review proceedings (2024/307 JR). The High Court (Holland J) quashed this second refusal and remitted the matter to the Commission by order of 29 July 2024.
Third refusal of leave (21 August 2024)
The present judicial review challenged this third refusal. The Commission and the notice party opposed the challenge.

2.3 The inspector’s assignment and the functus officio issue

The critical procedural irregularity, as identified in the principal judgment, concerns the timing of the assignment of an inspector under s.146 PDA:

After the Commission conceded that the second refusal of leave (9 January 2024) was invalid, but before the High Court formally quashed that decision and remitted the matter (i.e. between 5 July 2024 and 29 July 2024), a Director of Planning (lawfully authorised under s.146(1)) directed an inspector to prepare a report or memorandum on the application.
The inspector’s report and recommendation are dated 31 July 2024, two days after the remittal order. Farrell J found as a fact that the direction to assign the inspector was given before 29 July 2024, when the Commission was still functus officio in respect of the application (because the second refusal had not yet been quashed).
The inspector had probably begun work before remittal, though the report and recommendation were finalised afterwards.

In the principal judgment, Farrell J held that the Commission had no power to assign an inspector under s.146 in the period between the second refusal (9 January 2024) and the remittal order (29 July 2024. The Commission was functus officio and could not take any step which had legal effect in relation to the determination of the application.

However, she ultimately exercised her discretion to refuse certiorari of the third refusal of leave, viewing the timing irregularity as a de minimis breach which did not justify quashing the decision in all the circumstances.

2.4 The failed substantive challenge and the focus of this judgment

In the principal judgment, the applicant failed in his challenge to:

the Commission’s substantive assessment of the s.37(6)(d)(ii) criteria; and
the contents and reasoning of the inspector’s memorandum.

He has not sought a certificate to appeal any of those substantive findings. Instead, his certificate application targets the court’s treatment of the functus officio issue and its decision not to grant certiorari despite the procedural illegality.

2.5 The proposed question for certification

The applicant asked the High Court to certify the following as a point of law of exceptional public importance:

“What steps (administrative or other) can An Bord Pleanala (as it then was) take where this Honourable Court has determined that, at the time the Applicant’s application for leave to appeal was assigned to the Inspector and in respect of which the Inspector commenced consideration of same, the Board was in fact functus officio in circumstances where the Order had not been made nor had the terms of the Order been agreed and therefore the Board was deprived of jurisdiction to take any step administrative or other in respect of the determination of the application in accordance with law?”

Farrell J refused to certify this question, concluding that:

no point of law of exceptional public importance arose from the judgment; and
even if it did, an appeal would not be desirable in the public interest.

3. Summary of the Judgment

The judgment does three main things:

Restates the statutory test under s.50A(7) PDA.
A certificate may only be granted if:
- the decision involves a point of law of exceptional public importance; and
- it is desirable in the public interest that an appeal be taken to the Court of Appeal.
These requirements are cumulative and must be applied “sparingly”.
Holds that the applicant’s proposed question does not meet the first limb.
The proposed question:
- does not accurately reflect what the principal judgment decided;
- invites a broad advisory essay from the Court of Appeal on what steps the Commission may take while functus officio;
- would not, even if answered in the applicant’s favour, alter the outcome, because the High Court’s refusal of certiorari was an exercise of discretion based on case-specific factors; and
- does not expose any genuine legal uncertainty in the existing case law.
Accordingly, no “point of law of exceptional public importance” arises.
Finds that an appeal would not be desirable in the public interest.
Reasons include:
- the extensive delay already suffered, through no fault of the notice party, in determining the An Taisce appeal;
- the applicant’s ability to participate fully as an observer in that appeal, where he has already lodged observations;
- the limited practical effect even of a successful appeal (it would simply lead to yet another Commission decision on leave to appeal, without materially altering the substantive issues); and
- the legislative policy that High Court decisions in planning judicial review are generally final, and certification should be reserved for limited, exceptional cases.

The application for a certificate is therefore refused, and the High Court’s principal judgment remains final.

4. Statutory and Doctrinal Framework

4.1 Section 37(6) PDA – leave to appeal by non-participants

Under s.37(6) PDA, a person who did not make submissions or observations to the planning authority may be permitted to appeal a grant of permission to the Commission only in tightly limited circumstances. Section 37(6)(d) sets out conditions that must be satisfied. It was not disputed that:

if the Commission found those conditions were satisfied, it had to grant leave to appeal; and
if they were not satisfied, the Commission had no discretion to grant such leave.

The applicant’s challenge to the Commission’s findings under s.37(6)(d)(ii) failed in the principal judgment and is not the subject of the certification application.

4.2 Section 146 PDA – assignment of inspectors

Section 146 allows the Commission (or authorised staff) to assign an inspector to prepare a report or memorandum on an application. In the principal judgment, Farrell J accepted that:

the Director of Planning was duly authorised to assign an inspector under s.146(1); but
there was no power to make such an assignment at a time when the Commission was functus officio in respect of that application (i.e. after it had already determined the s.37(6) application and before any High Court order quashed that decision and remitted the matter).

4.3 Section 50A(7) PDA – certification for appeal to the Court of Appeal

Section 50A(7) governs appeals from planning judicial review decisions. The High Court may only certify a point of law for appeal where:

the decision involves a point of law of exceptional public importance; and
it is desirable in the public interest that an appeal be taken.

The two criteria are cumulative. The Oireachtas has decided that, in most planning judicial review cases, the High Court’s decision is final, and certification must be “exercised sparingly”.

4.4 Functus officio and certiorari – basic concepts

Two procedural concepts underpin the case:

Functus officio: Once a decision-maker has made a final decision on a matter, it is said to be functus officio – its function is exhausted. It cannot revisit, amend or take further steps which affect the legal position of the parties, unless some fresh statutory or judicial basis restores its jurisdiction (e.g. a remittal order following judicial review).
Certiorari: A form of judicial review remedy by which the High Court quashes an impugned decision. Even where unlawfulness is established, the court retains a residual discretion whether to grant certiorari, particularly where a breach is de minimis (trivial or technical) and produces no real prejudice or expansion of jurisdiction.

5. Precedents Cited and their Influence

5.1 Certification jurisprudence under s.50A(7)

(a) Monkstown Road Residents Association v An Bord Pleanála [2023] IEHC 9

All parties relied on Monkstown Road, and Farrell J treated it as a key authority. Holland J’s summary, cited at para. 8–9 of the present judgment, distilled the following principles:

The High Court’s decision in most planning judicial reviews is final. Certification is exceptional; the jurisdiction is to be exercised sparingly.
The proposed appeal must raise a point of law of exceptional public importance, not merely an arguable or interesting legal point.
It must also be desirable in the public interest that the appeal be taken.
A valid point of law for certification should be determinative or at least capable of altering the result; if answering the question differently would not change the outcome, the point is moot and unsuitable for certification.
A certified question must not invite the appellate court “to write an essay” or give a roving, advisory opinion on a subject; it must be a focused, concrete question arising from the judgment itself.

Farrell J drew heavily on these principles to reject the applicant’s proposed question as:

over-broad and advisory in nature; and
not determinative of the outcome of the principal judgment, which turned on discretionary factors.

She also adopted Holland J’s warning that “uncertainty” cannot simply be imputed to the law by framing a question which the Court has already answered; the uncertainty must arise in the operation of the law beyond the particular case.

(b) Leech & Anor v An Bord Pleanála [2025] IEHC 157 and GOCE Ltd v An Bord Pleanála [2025] IEHC 43

While the present judgment does not detail these cases, Farrell J notes that she has “also considered the applicable principles” in them. Their relevance lies in reaffirming and applying the same restrictive approach to certification: emphasizing that the thresholds of “exceptional public importance” and “public interest” are cumulative and high.

(c) Massey v An Bord Pleanála (No. 4) [2025] IEHC 309 and S.A. v Minister for Justice and Equality (No. 2) [2016] IEHC 646

Humphreys J in Massey (No. 4), referring to S.A. (No. 2), stressed that a certified point of law generally should not be one which, even if answered in favour of the appellant, leaves the ultimate result unchanged. This reaffirms the “determinative” requirement and the prohibition on moot or purely academic points.

Farrell J uses these authorities to support the proposition that:

A question about what the Commission could hypothetically do while functus officio – when the real dispute has already been resolved in the principal judgment – is not determinative of the relief granted or refused.
The High Court’s exercise of discretion in refusing certiorari is case-specific; re-litigating that discretion does not, without more, raise a point of law of exceptional public importance.

(d) Stapleton v An Bord Pleanála [2025] IEHC 178

Stapleton is cited for the proposition (echoing Monkstown Road and S.A. (No. 2)) that a certified question must not be an invitation to an appellate court to provide a “discursive, roving response”. This directly undermines the applicant’s expansive question about “what steps (administrative or other) can” the Commission take while functus officio.

5.2 De minimis breaches and the discretion to refuse certiorari

(a) Cases on public participation and jurisdictional defects

The applicant argued that the principal judgment created uncertainty about when a court may decline to grant certiorari in the face of a breach of a statutory scheme. He contended that certiorari can only be refused if the breach is de minimis, and relied on:

Southwood Park Residents Association v An Bord Pleanála [2019] IEHC 504
McAnenley v An Bord Pleanála [2002] IEHC 60; [2002] 2 I.R. 763
Electricity Supply Board v Gormley [1985] I.R. 129
Graves v An Bord Pleanála [1997] IEHC 96; [1997] 2 I.R. 205

From the way Farrell J describes them:

These cases emphasise that breaches affecting public participation rights are rarely truly trivial and often cannot be cured by the de minimis doctrine.
In Graves, the Board had no jurisdiction to entertain an appeal because it was lodged out of time. This was not a mere technical irregularity: the Board’s acceptance of an out-of-time appeal fundamentally expanded its jurisdiction in a way the statute did not allow.

Farrell J distinguishes the present case from such situations: while the Commission acted outside the four corners of the Act by assigning an inspector too early, it did not:

expand its jurisdiction;
affect any deadlines for appeals; or
infringe public participation or third-party rights.

(b) Murphy v Cobh Town Council [2006] IEHC 324; Ní Chonghaile v Galway County Council [2004] IEHC 317; [2004] 4 I.R. 138; and Monaghan UDC v Alf-a-Bet Promotions Ltd [1986] ILRM 64

In Murphy, MacMenamin J reviewed the de minimis doctrine in public law and concluded that where there is substantial compliance with statutory requisites and no meaningful prejudice, a court may treat a breach as trivial or technical and refuse certiorari.

He cited Ní Chonghaile, where the High Court held that the de minimis rule should be applied because the public had not been misled and “the spirit of the regulation was more important than its letter”. That case, like the present one, involved the court’s discretionary refusal of certiorari despite a technical breach.

He also relied on Henchy J’s analysis in Alf-a-Bet Promotions, identifying deviations that are “trivial”, “technical” or “peripheral” – classic de minimis situations where an otherwise mandatory requirement has been substantially complied with.

Farrell J expressly aligns her approach with this line of authority. Even though she did not use the words de minimis in the principal judgment, she makes clear in this certification judgment that:

the Commission’s breach was non-substantial;
there was substantial compliance with the statutory scheme overall; and
no real prejudice or expansion of jurisdiction ensued.

Accordingly, she concludes that her refusal of certiorari is entirely consistent with Murphy, Ní Chonghaile and Alf-a-Bet.

(c) Time limits as non-trivial breaches: McCann v An Bord Pleanála [1997] 1 I.R. 264 and Rowan v An Bord Pleanála [2006] IEHC 180

In McCann and Rowan, the Board failed to comply with mandatory statutory time limits. MacMenamin J in Murphy considered that such failures involved substantive or fundamental non-fulfilment of procedural requirements, comparable to failing to issue a summons within a limitation period. They could not be dismissed as de minimis.

Farrell J contrasts these with the present case. The Commission did not miss any statutory deadlines, nor did it assume jurisdiction where none existed. The only defect was the premature assignment of an inspector, with no discernible impact on the integrity of the procedure or the applicant’s rights.

6. The Court’s Legal Reasoning

6.1 No point of law of exceptional public importance

(a) The judgment did not authorise the Commission to act while functus officio

The applicant claimed that the principal judgment created uncertainty about what steps the Commission can take when it is functus officio, suggesting the Court had effectively endorsed certain administrative actions during that period.

Farrell J rejects that characterisation. She clarifies that:

The only step she found to be unlawful was the assignment of an inspector under s.146(1) before the remittal order. She expressly held at para. 79 of the principal judgment that she was “not persuaded that the power to assign an Inspector to prepare a report existed before the remittal order was made”.
At para. 75, she found that the parties’ agreement that the prior decision should be quashed did not remove the functus officio status of the Commission and did not authorise it to take steps producing legal effects in relation to the application.
The only actions she indicated were permissible while functus officio were:
- defending the judicial review proceedings; and
- “housekeeping” such as reading or moving the file in preparation for a likely remittal.

Accordingly, far from broadening the Commission’s powers while functus officio, the principal judgment:

re-affirmed that no exercise of statutory decision-making powers is permitted in that phase; and
found the premature inspector assignment to be ultra vires.

On that basis, the “uncertainty” alleged by the applicant is not borne out by the text of the judgment.

(b) The proposed question invites an advisory essay

The applicant’s question – “What steps (administrative or other) can [the Commission] take … while functus officio?” – is, in Farrell J’s view, a classic example of the sort of question the appellate courts have refused to entertain under s.50A(7):

It does not arise as a concrete issue requiring resolution to decide the case; the principal judgment already identified one step (assignment under s.146) as unlawful and others (defending proceedings, moving files) as permissible.
It would require the Court of Appeal to give a wide-ranging, general advisory opinion on an array of hypothetical scenarios – something explicitly disapproved in S.A. (No. 2), Massey (No. 4), Stapleton and Monkstown Road.

(c) The point is not determinative of the outcome

Even if the Court of Appeal were to answer the applicant’s question in his favour, this would not necessarily change the result of the case. The crux of the principal judgment was not:

that the Commission had acted lawfully while functus officio; but
that, despite the unlawful step, the High Court exercised its discretion to refuse certiorari, taking account of a range of factors (para. 22 of the present judgment).

Since the decision turned on discretion, and not on a pure point of law about the scope of powers while functus officio, an answer to the proposed question would not be determinative. Under Monkstown Road and Massey (No. 4), such a question does not qualify as a point of law of exceptional public importance.

(d) No genuine legal uncertainty is demonstrated

The applicant argued that the judgment created uncertainty about how to interpret earlier case law, especially concerning when a breach of the statutory scheme may be treated as de minimis. Farrell J disagrees:

She emphasises that merely disagreeing with a judgment or rephrasing its reasoning as a question does not establish “uncertainty” in the legal system. Under Monkstown Road, uncertainty must be shown to arise in the daily operation of the law, not simply because a party is unhappy with the outcome.
She concludes that her approach to de minimis breaches and discretion is wholly consistent with previous authorities (especially Murphy, Ní Chonghaile, Alf-a-Bet, McCann, Rowan and Graves), and that no tension or ambiguity is introduced.

Thus, the first limb of s.50A(7) is not satisfied.

6.2 Discretion and the de minimis breach

(a) Why the breach was regarded as de minimis

The unlawfulness identified – the premature assignment of the inspector – was treated as a de minimis breach based on several key features:

The assignment was made by a properly authorised official (the Director of Planning).
The inspector’s report and recommendation were completed after the application was properly remitted on 29 July 2024, at which point the Commission had jurisdiction.
There was no impact on public participation, no infringement of time limits, and no impairment of any third-party rights.
The Commission did not assume any jurisdiction it would not otherwise have had. Unlike Graves, no out-of-time appeal was accepted; jurisdiction arose from the valid s.37(6) application and the subsequent remittal.
The applicant could identify no prejudice or change in how his application was or could have been considered had the inspector been assigned only after the remittal date.
The applicant had already failed in his substantive challenge to the decision on s.37(6); the only remaining issue was a technical timing irregularity.

Taken together, these factors show the court’s willingness to view certain ultra vires steps as de minimis where they do not affect the fairness, integrity, or scope of the decision-making process.

(b) Broader discretionary factors (para. 22)

In refusing certiorari in the principal judgment, Farrell J relied on a multi-factor discretionary assessment, including:

The lawfulness of the officer’s authority to assign inspectors in general.
The timing of the report’s completion, after jurisdiction had been restored.
The clear expectation among the parties that the application would be remitted, following the Commission’s concession of invalidity.
The absence of unfairness or prejudice caused by the early assignment.
The applicant’s failure on the substantive grounds of challenge.
The existence of an extant appeal by An Taisce, on which the applicant had made submissions and which would raise essentially the same issues as any appeal he might bring.
The legislative policy that non-participants at first instance have no right of appeal, subject to the narrow exception in s.37(6).
The developer’s prolonged exposure to delay despite having no responsibility for the procedural errors or litigation.
The proportionality of quashing the decision in light of the minimal nature of the breach and the availability of an ongoing appeal mechanism (the An Taisce appeal).

This holistic balancing underscores that the outcome is heavily fact-dependent; it does not rest on a novel point of law of general application, reinforcing the refusal to certify.

6.3 Public interest and the undesirability of an appeal

Although not strictly necessary once she found no point of law of exceptional public importance, Farrell J also addresses the second limb of s.50A(7) – whether an appeal would be desirable in the public interest.

She concludes it would not, emphasising:

The planning permission application dates back to November 2022; the Council’s decision is from February 2023; yet the appeal has still not been determined because of three sets of judicial review proceedings.
The delay is not attributable to the notice party, who has a legitimate interest in finality.
An appeal to the Court of Appeal would further delay the determination of An Taisce’s appeal, which is in the public interest to resolve promptly.
Even if the applicant succeeded in the Court of Appeal and certiorari were granted, the likely practical effect is only that the Commission would make a fourth decision on leave to appeal. The substantive issues would remain substantially the same, given the overlap between the applicant’s proposed grounds and the issues already raised in An Taisce’s appeal.
The Oireachtas has deliberately restricted the circumstances in which non-participants can appeal and the circumstances in which High Court planning judicial review decisions may be appealed.

Thus, even if a qualified point of law existed, the balance of public interest lies in allowing the Commission to proceed to determine the existing An Taisce appeal rather than prolonging litigation over a technical timing irregularity.

7. Complex Concepts Simplified

7.1 Functus officio in simple terms

A decision-maker is functus officio when its job in relation to a particular matter is finished. Once it has made its decision:

it cannot change that decision;
it cannot take new steps that affect the parties’ legal rights in that case; and
it can only act again if a court or a statute gives it a fresh mandate (for example, after a judicial review court quashes the decision and formally sends the case back to it).

In this case, once the Commission made its second refusal of leave on 9 January 2024, it was functus officio in relation to that s.37(6) application until the High Court quashed that refusal and remitted the matter on 29 July 2024.

7.2 De minimis breaches

De minimis literally means “about minor things”. In legal terms, a de minimis breach is a violation of a rule that is so small, technical, or harmless that the court may decide not to undo the decision because of it.

Courts look at questions such as:

Has there been substantial compliance with the statutory requirements overall?
Has anyone been misled or disadvantaged?
Has the decision-maker assumed a power it plainly did not have (for example, extending a time limit or accepting an appeal out of time)?
Would quashing the decision be proportionate, given the nature of the error and the consequences of starting again?

In Morehart, the breach (prematurely assigning an inspector) did not mislead or prejudice anyone, and did not expand the Commission’s jurisdiction. The High Court therefore treated it as de minimis.

7.3 Certification under s.50A(7)

Not every error – or alleged error – in a planning judicial review can be appealed to the Court of Appeal. Section 50A(7) sets a high bar. A certificate will only be granted if:

The case raises a point of law – a legal question, not just a disagreement about facts or about how the judge exercised discretion.
The point of law is of exceptional public importance – it must matter beyond the parties, affect many future cases, or clarify a seriously uncertain area of law.
An appeal is desirable in the public interest – considering delay, cost, finality, and the broader planning system.

Even then, the question must be focused, not a request for a general “essay” on a topic.

8. Impact and Implications

8.1 For An Coimisiún Pleanála and its procedures

The judgment has immediate operational implications for the Commission:

It confirms that the Commission cannot lawfully assign inspectors or take other decision-making steps under the PDA while it is functus officio. A concession in court that its earlier decision is invalid does not itself revive jurisdiction; only a formal court order quashing and remitting does.
However, it also reassures that not every technical misstep will automatically lead to quashing. Where an error is truly de minimis, does not affect jurisdiction or participation rights, and causes no prejudice, the court may exercise discretion to leave the decision in place.

This strikes a balance between:

ensuring strict compliance with statutory powers; and
avoiding disproportionate disruption of planning processes over harmless irregularities.

8.2 For litigants and planning objectors

For applicants considering judicial review:

The case illustrates the limits of challenges grounded solely on technical or timing irregularities, especially where no practical prejudice is shown.
It underlines the importance of participating in the planning authority’s process if one wishes to have a right of appeal; the Oireachtas has deliberately constrained the ability of non-participants to seek leave to appeal under s.37(6).
It warns that efforts to obtain certification for appeal under s.50A(7) will fail if framed as broad, advisory questions or if divorced from concrete, determinative points of law arising from the particular judgment.

8.3 For the development and public interest in finality

From a systemic perspective, the judgment reinforces the public interest in:

timely resolution of planning appeals, particularly where a valid third-party appeal (here, by An Taisce) is already pending;
finality for developers who have not contributed to procedural errors; and
avoiding unnecessary layers of litigation that do not materially affect the substantive outcome.

The emphasis on proportionality and delay in assessing the desirability of further appeals is likely to discourage technical challenges that risk stalling major projects without a corresponding public benefit.

8.4 For the doctrine of discretion in judicial review

The judgment contributes to the maturing of the Irish doctrine that even where illegality is identified, relief is not automatic. Its key messages include:

Courts will examine the real-world impact of the illegality, including whether it has affected rights, jurisdiction, participation, or the integrity of the process.
The availability of alternative avenues (here, the An Taisce appeal, on which the applicant has made submissions) may weigh against quashing.
Technical or de minimis breaches, particularly in the administrative preparation of a case, will not necessarily warrant certiorari where substantial compliance and absence of prejudice can be shown.

In future judicial reviews, Morehart will likely be cited to show that:

courts retain a robust remedial discretion; and
litigants must demonstrate not just error, but why quashing is necessary and proportionate in the circumstances.

9. Conclusion

Morehart v An Coimisiún Pleanála [2025] IEHC 701 is significant less for any radical doctrinal innovation than for the way it consolidates and clarifies existing principles in three interconnected areas of planning law and judicial review:

Functus officio and the limits of administrative action
The Commission cannot exercise its statutory powers – such as assigning inspectors under s.146 – in relation to an application once it has become functus officio. A mere concession of invalidity does not revive jurisdiction; only a court order quashing and remitting does. Permissible steps in the functus officio phase are confined to defending proceedings and neutral “housekeeping”.
De minimis breaches and the discretion to refuse certiorari
The High Court may, in appropriate cases, treat certain procedural breaches as de minimis, particularly where:
- there is substantial compliance with statutory requirements overall;
- no prejudice, expansion of jurisdiction, or impairment of participation rights arises; and
- quashing would be disproportionate in light of delay, alternative safeguards, and the position of third parties such as developers.
Farrell J’s approach is explicitly grounded in and consistent with existing authorities such as Murphy, Ní Chonghaile, Alf-a-Bet Promotions, McCann, Rowan and Graves.
The narrow gateway for appeals under s.50A(7) PDA
The judgment reinforces that certification:
- is exceptional and must be exercised sparingly;
- requires a focused point of law of exceptional public importance that genuinely arises from the judgment;
- demands that the point be determinative or capable of changing the outcome; and
- must be assessed in light of whether an appeal is desirable in the public interest, taking into account delay, finality, and the broader planning process.
Attempts to frame broad, essay-type questions or to use certification to re-litigate discretionary remedial decisions are unlikely to succeed.

Taken together, these elements make Morehart an important authority for practitioners in planning law, for the Commission in managing remittals and internal procedures, and for litigants contemplating judicial review or appeals under s.50A(7). It signals a judicial preference for proportionality, finality, and substantive justice over the automatic nullification of decisions for every technical flaw, while preserving strict legal limits on the exercise of statutory powers by a decision-maker that has become functus officio.

(This commentary is for informational and educational purposes only and does not constitute legal advice.)