M v M (Approved)

Factual and Procedural Background

This Supreme Court appeal concerned the courts’ jurisdiction to restrict a serial or vexatious litigant from initiating further proceedings (commonly via an “Isaac Wunder” order), specifically in family law proceedings involving child access and maintenance.

The Appellant and Respondent were formerly in an intimate relationship and have one minor child. They have been engaged in access and maintenance proceedings since 2012. In December 2015 the District Court varied an access order. The Respondent appealed to the Circuit Court, which—after more than forty listings—made a final determination on access and maintenance in May 2022, including specific access arrangements and maintenance-related orders.

The Circuit Court attributed increased litigation costs to the Appellant’s unmeritorious conduct (including persistent breaches and repeated applications) and ordered the Appellant to pay 50% of the Respondent’s costs. During costs submissions, counsel for the Appellant suggested repeated litigation could instead be addressed through an Isaac Wunder order. The Circuit Court made such an order of its own motion, restricting the Appellant from taking further proceedings against the Respondent in the District Court, Circuit Court, or any other court without leave of the Circuit Court.

In August 2022, the Appellant obtained ex parte leave from the High Court to seek judicial review, including an order of certiorari to quash the Circuit Court order of May 2022. The Respondent moved to set aside that leave, contending (among other matters) material factual incorrectness and breach of the Isaac Wunder order.

In March 2023, the High Court (Judge Simons) held that the Circuit Court could not require its leave before judicial review in the High Court (as this would frustrate the High Court’s supervisory jurisdiction). The High Court also set aside the grant of leave due to material non-disclosure and misleading characterisation of the Circuit Court proceedings.

In February 2024, the Court of Appeal upheld the setting aside of leave for material misstatements/non-disclosure, but held that the non-disclosure was not material to a challenge to the Isaac Wunder order and varied the order accordingly. In June 2024, the Court of Appeal, with the parties’ agreement, quashed the Circuit Court’s Isaac Wunder order and entertained a fresh application, ultimately making an Isaac Wunder order restraining the Appellant from instituting proceedings against the Respondent (including appeals) in the District Court, Circuit Court, High Court, or Court of Appeal without prior leave of the President of the relevant court or a nominated judge.

In October 2024, the Appellant obtained leave to appeal to the Supreme Court. The Attorney General was joined as a notice party due to the broader importance of the issues. In January 2026, Judge Dunne delivered the Supreme Court judgment.

Legal Issues Presented

1. Is a court dealing with child access and/or maintenance applications entitled to make an Isaac Wunder order against a party?
2. If so, what is the basis on which such an order may be made?
3. Did the Court of Appeal err in making the Isaac Wunder order in this case?
4. What powers may a court generally exercise when faced with a serial litigant or someone who repeatedly prolongs/disrupts proceedings, including by misrepresenting what occurred in court previously?

Arguments of the Parties

Appellant’s Arguments

• Isaac Wunder orders in child access/maintenance proceedings risk disregarding the distinctive nature of family disputes, which often require ongoing court involvement.
• Any restraint must respect the child’s best interests (Article 42A), the constitutional right of access to the courts (Article 40.3), and Convention rights (Article 6 fair trial; Article 8 private and family life), and should include strict safeguards.
• The preliminary leave requirement may cause time, expense, and delay that could impair timely access decisions and risk loss of contact through passage of time.
• Ireland’s approach was said to lack the structured proportionality and oversight found in other jurisdictions (notably the UK’s graduated civil restraint orders), making Irish orders potentially overbroad, indefinite, and insufficiently reviewable.
• The Court of Appeal allegedly failed to consider less intrusive alternatives and to give adequate reasons for a blanket and indefinite order; a time-limited or issue-specific order was argued to be more proportionate.
• More generally, restrictions on litigation should comply with proportionality and legal certainty, and should be tailored to the specific disruptive conduct.

Respondent’s Arguments

• A court may, via inherent jurisdiction/powers, make an Isaac Wunder order in exceptional circumstances to protect a custodial parent and child from oppressive, protracted litigation, especially given the accessibility of family court applications and legal aid.
• The order does not abrogate access to the courts; it operates as a proportionate “filtering mechanism” to protect against significant (often unrecoverable) costs and harassment.
• ECtHR authority recognises domestic courts’ ability to control abuse of process; the Appellant’s ECtHR cases were distinguished as concerning procedural unfairness in access determinations rather than restraint orders.
• If Article 8 is engaged, the interference was said to be legitimate, necessary, and proportionate, because leave can be obtained quickly where further proceedings are genuinely required.
• UK authority was cited to show civil restraint orders may be used exceptionally even in child proceedings; and prolonged litigation may itself harm the child’s welfare and the custodial parent’s financial stability.
• The Court of Appeal order was justified on the exceptional facts and was said to be necessary to prevent abuse and protect the Respondent and child.

Attorney General’s Submissions

• The Isaac Wunder order is one tool within the courts’ inherent powers to protect both (i) private interests (shielding parties from harassment/expense) and (ii) the public interest (protecting court resources and process).
• There is no principled reason restraint orders cannot apply in family law, but they should be used sparingly and in a child-centred manner given additional constitutional considerations.
• Irish law provides multiple tools for serial litigants (strike-out, dismissal for conduct, party-specific restraint orders, security for costs, contempt), but any limitation must satisfy proportionality and preserve the essence of access to court.
• Domestic authorities were cited showing restraint orders (including in child-related proceedings) are sometimes constitutionally permissible, depending on the facts.

Table of Precedents Cited

Court's Reasoning and Analysis

Nature of the jurisdiction and balancing exercise. The Court reaffirmed that Irish courts have inherent powers to protect court processes from abuse and to protect other parties from unnecessary harassment and expense. While access to justice is constitutionally protected, it is not unlimited: repeated frivolous, vexatious, or abusive litigation can justify restrictions. The Court reviewed rule-based strike-out mechanisms (including O.19, r.28 RSC as amended) and inherent-jurisdiction/power doctrines permitting summary disposal of proceedings that are bound to fail or constitute abuse of process.

Isaac Wunder orders as exceptional “filtering” measures. The Court characterised Isaac Wunder orders as exceptional and to be deployed sparingly. Their essential feature is not a substantive bar on litigation but a procedural requirement to obtain leave before instituting further proceedings against the protected party. The Court emphasised that leave should be granted where a bona fide, arguable claim is shown and is not a vexatious repetition of earlier grievances already determined.

Family law context and best interests of the child. The Court held there is no bar in principle to making Isaac Wunder orders in family law proceedings concerning access/maintenance/custody. It accepted that family law disputes may require future applications due to changes in circumstances and that courts must consider the child’s best interests when deciding whether to impose restraint. However, the Court rejected the proposition that Article 42A could justify endless abusive litigation; it considered that repetitious, unmeritorious litigation may itself harm the child (stress, acrimony, repeated assessments) and deplete the custodial parent’s resources.

Convention rights. The Court distinguished ECtHR cases relied on by the Appellant as dealing with substantive restrictions on parental access and procedural unfairness in those proceedings, rather than leave-based filters designed to prevent abuse. It accepted that restrictions on access to court must pursue a legitimate aim and be proportionate, but found nothing in ECtHR jurisprudence that prohibited proportionate restraint orders.

Jurisdiction of courts of local and limited jurisdiction. The Court agreed that the Circuit Court could not restrict access to the High Court (and thus could not require Circuit Court leave before judicial review), affirming Judge Simons’ reasoning on the High Court’s supervisory jurisdiction and full original jurisdiction. However, the Court concluded that the Circuit Court and District Court, as constitutional courts administering justice, have inherent power to make Isaac Wunder orders to prevent abuse of their own processes within their jurisdictional limits. The Court discussed the “local and limited” requirement and emphasised that inferior courts cannot make orders restricting proceedings in courts of greater constitutional jurisdiction.

No error in the Court of Appeal order. The Court held the Court of Appeal had properly applied the relevant factors to a history described as a barrage of unmeritorious litigation, and had regard to evidence including the effect on the child. It rejected the argument that less restrictive measures had to be exhausted first as a matter of principle, noting the leave mechanism preserves access where a legitimate case arises and can be dealt with expeditiously.

Misrepresentation of prior proceedings and procedural protections. Addressing issue (4), the Court identified multiple tools available to courts dealing with serial or disruptive litigants (strike-out/dismissal, costs, security for costs, case management, contempt, and obtaining transcripts). It endorsed the setting-aside of judicial review leave where obtained on a grossly misleading factual basis and highlighted the importance of digital audio recording as a safeguard against misrepresentation of prior hearings.

Holding and Implications

DISMISSED. The Supreme Court dismissed the appeal and affirmed the Court of Appeal’s order.

Implications. The direct effect was that the Isaac Wunder order made by the Court of Appeal remained in place, requiring the Appellant to obtain prior leave before instituting proceedings against the Respondent in the specified courts. The judgment confirmed that Isaac Wunder orders may be made in family law proceedings (including access and maintenance disputes) where proportionate and necessary, with the child’s best interests being a relevant factor. It also affirmed that the Circuit Court cannot restrict recourse to the High Court, while indicating that the Circuit Court and District Court may exercise inherent powers to prevent abuse within their own jurisdictional limits. The Court framed such orders as exceptional, leave-based filters rather than absolute prohibitions, and emphasised available procedural mechanisms to address misleading ex parte applications and serial litigation conduct.