No-order-as-to-costs for unsuccessful “pathfinder” public interest judicial reviews where the litigation resolves a holding-list cohort without clarifying uncertain law

Case: MJ v The Minister for Justice, AA v. The Minister for Justice [No. 2] (Approved) [2026] IEHC 390
Court: High Court (Bradley J.)
Date: 18 June 2026
Context: Costs ruling following the principal judgment in MJ and AA v The Minister for Justice [2026] IEHC 51

2. Summary of the Judgment

• The Court accepted that the proceedings satisfied the criteria for “public interest” litigation as described in Little v The Chief Appeals Officer & Ors (No. 2) [2024] IESC 53 (“Little (No. 2)”).
• However, the Court held the cases were not within the “exceptionality” threshold (as discussed in Little (No. 2)) that could justify awarding costs to the unsuccessful applicants (even partially).
• Balancing the relevant factors, the Court exercised its discretion to make no order as to costs (each side bears its own costs) in both proceedings.

3. Analysis

3.1 Precedents cited and their role

(a) Little v The Chief Appeals Officer & Ors (No. 2) [2024] IESC 53

Little (No. 2) was the centrepiece. Bradley J. treated it as governing the modern Irish approach to costs in public interest proceedings, including:

• Discretion to withhold costs against an unsuccessful applicant: At para. 68 (as referenced), Murray J. affirmed a High Court discretion not to award costs against an unsuccessful plaintiff/applicant in public interest proceedings.
• Balancing exercise with non-exhaustive factors: At para. 69 (as referenced), Murray J. required regard to “all the facts and circumstances” and identified non-exhaustive factors (referenced here as being set out at para. 35 in Little (No. 2)).
• Personal interest not automatically disqualifying: The judgment records the applicants’ reliance on the proposition (para. 35(ii) of Little (No. 2)) that an applicant having a personal stake does not, of itself, preclude public interest treatment on costs.
• “Exceptionality” for costs to an unsuccessful party: Bradley J. held these proceedings did not meet the “exceptionality” described at para. 71 of Little (No. 2), and therefore refused to award any portion of costs to the unsuccessful applicants.
• Pathfinder/representative case factor: By analogy with para. 35(iv) of Little (No. 2), the Court treated the agreed selection of MJ and AA as pathfinder cases from a large cohort as a weighty factor supporting a “no order as to costs” outcome.

(b) Authorities referenced in the principal judgment (mandamus/delay) and their indirect costs significance

While this judgment is about costs, the Court evaluated the nature and strength of the underlying litigation through the lens of the principal judgment, which applied established mandamus principles to delay in naturalisation decision-making. The costs analysis therefore referenced, in particular:

• Singh v The Minister for Justice and Equality; Zydek v The Minister for Justice and Equality; Shahid Arshad v The Minister for Justice and Equality [2022] IEHC 437 (“Singh”): relied upon in the principal judgment for the threshold that delay must be “so egregious and unjustified” as to be tantamount to a refusal in effect.
• Point Exhibition Co. Ltd v The Revenue Commissioners [1993] 2 I.R. 551: cited in the principal judgment and indicative of the established nature of the principles being applied.

That background mattered because Bradley J. distinguished between (i) pathfinder cases that simply apply settled principles to many factually similar claims, and (ii) pathfinder cases that clarify uncertain or ambiguous legislation. Only the latter category is more likely to justify more exceptional costs outcomes for an unsuccessful party.

(c) Other costs-related references

• Daly and Murphy v An Taoiseach and Ors [2026] IEHC 133 (mentioned as a costs discussion in joint cases), including reference to Curtin v Dáil Éireann [2006] IESC 27: relied upon by the applicants in arguing for partial costs despite losing, but ultimately not accepted on the facts given the absence of the requisite “exceptionality”.

3.2 Legal reasoning

(a) Starting point: presumptive entitlement of the successful party

The Minister argued that, having succeeded, the default rule applied under s. 169(1) of the Legal Services Regulation Act 2015 (the “2015 Act”): costs follow the event unless the court orders otherwise. Bradley J. accepted this as the starting point, but emphasised (via Little (No. 2)) that it is not the end point in public interest litigation.

(b) Public interest status accepted, but not “exceptionality” for applicant-cost recovery

The Court recorded that the parties accepted the cases met the public interest criteria (referencing para. 68 of Little (No. 2)), particularly because:

• They were selected pathfinder cases expected to affect a large cohort of similar proceedings (the holding list).
• They addressed a recurring legal argument about delay/mandamus in naturalisation processing.

Nevertheless, Bradley J. refused to award any portion of the applicants’ costs because the proceedings did not fall within the “exceptionality” contemplated in Little (No. 2) (para. 71 as referenced). A key reason was that the litigation involved applying established mandamus principles rather than resolving unclear statutory meaning.

(c) The pivotal costs outcome: “no order as to costs” despite the Minister’s success

The judgment’s core move is the distinction between two potential “public interest” costs consequences:

• (i) Shielding an unsuccessful applicant from an adverse costs order (a protective “no order” outcome).
• (ii) Compensating an unsuccessful applicant by awarding costs against the successful respondent (a rare, exceptional outcome).

Bradley J. held that (ii) was not justified, but (i) was. In exercising the balancing discretion (per para. 69 of Little (No. 2)), the Court relied on several case-specific features:

• Pathfinder selection from a large cohort: The applicants’ cases were treated by all parties as representative test cases, selected to determine a legal argument raised in many pending claims (explicitly linked to the factor in para. 35(iv) of Little (No. 2) by analogy).
• Systemic benefit primarily case-management efficiency, not legal novelty: The “systemic importance” lay mainly in disposing of many cases and concluding litigation, rather than in breaking new legal ground or clarifying uncertain legislation.
• Strength/nature of the underlying proceedings: The substantive claims failed under established mandamus principles; that reduced the justification for any more favourable costs order to the unsuccessful parties.
• Deterrence not established: The Court did not consider that awarding costs against the applicants would likely have a significant deterrent effect on the affected category (a factor often relevant in public interest costs analysis).

The result was a pragmatic public-law costs resolution: if parties (including the State) agree to run representative cases to resolve a backlog, the court may protect those applicants from adverse costs, even where the respondent succeeds and the law applied is settled.

3.3 Impact

• Encouragement of representative litigation without punitive cost exposure: Applicants whose cases are selected (often with the State’s agreement) as pathfinders for a larger cohort can argue more strongly for a “no order as to costs” outcome even if they lose.
• Clear limit on “paying the loser”: The judgment signals that merely being a pathfinder public interest case is unlikely to justify awarding costs to an unsuccessful applicant where the court is applying established principles (rather than clarifying uncertain statutory provisions).
• Sharper distinction in public interest costs jurisprudence: The decision reinforces a two-tier approach: (i) costs protection (no order) may be comparatively available; (ii) costs recovery by an unsuccessful party remains exceptional.
• Practical consequences for the naturalisation-delay holding list: While not determining those other cases directly, the costs ruling reduces the “pathfinder penalty” problem (where only the test-case litigants face adverse costs while similarly situated litigants benefit from the outcome).

4. Complex concepts simplified

• Mandamus: A court order compelling a public authority to perform a public duty. In delay cases, the key question is whether the authority’s inaction is so serious that it amounts to a wrongful refusal to decide.
• “Egregious and unjustified delay” tantamount to refusal: A high threshold used to decide whether delay becomes legally equivalent to a refusal (as applied in the principal judgment, referencing “Singh”).
• Public interest proceedings (for costs): Litigation that, beyond the individual’s stake, materially affects a wider class or addresses an issue of broader public importance. That status can justify shielding an unsuccessful applicant from adverse costs in the court’s discretion.
• Pathfinder/test case and holding list: Courts (often with parties’ agreement) select one or two representative cases to determine issues common to many similar cases placed in a “holding” queue. The outcome then guides resolution of the rest.
• “No order as to costs”: Each side pays its own costs. It is not a finding that either side behaved wrongly; it is a discretionary allocation based on fairness and the litigation’s character.

5. Conclusion

MJ v The Minister for Justice, AA v. The Minister for Justice [No. 2] [2026] IEHC 390 provides a focused costs precedent for public law case management: where judicial review proceedings are consciously run as pathfinder/test cases from a large cohort (including a holding list), the High Court may, even after dismissing the applications on established legal principles, refuse to award the successful public authority its costs and instead make no order as to costs.

At the same time, the judgment confirms the continuing strictness of the “exceptionality” threshold: being a public interest pathfinder does not, without more, justify awarding any portion of costs to an unsuccessful applicant.