Raising the bar: Irish Supreme Court confirms “strong case” test for pre-trial stays of regulatory decisions

In its landmark decision in TikTok Technology Limited & Anor v Data Protection Commission [2026] IESC 27, the Supreme Court raised the bar for granting interim pre-trial stays on decisions made by statutory regulatory bodies that have general public impact, emphasising that stays on such decisions should only be granted in the most exceptional circumstances.

An applicant must demonstrate a “strong case” that is likely to succeed at trial” before the court will consider whether the balance of convenience weighs in favour of granting a stay.  Even where a “strong case” is established, a stay will not automatically follow simply because the applicant will suffer irrecoverable financial loss. The Court considered irrecoverable expense incurred in complying with a regulatory decision, even one eventually quashed on review or appeal, to be a cost of conducting business in regulated sectors.

This is a materially higher threshold than the standard of showing an “arguable case” for administrative decisions affecting specific individuals (as opposed to regulatory decisions that impact the fundamental rights of a vast third party user base).

How did the parties end up before the Supreme Court?

The underlying dispute arose from a decision by the Data Protection Commission (the “DPC“), Ireland’s lead data protection supervisory authority, under the General Data Protection Regulation (“GDPR“).  The DPC found that TikTok had infringed the GDPR by failing to ensure adequate safeguards for the personal data of European Economic Area users whose data was accessed remotely by personnel in China.  Consequently, the DPC imposed fines of €530 million on TikTok and ordered it to suspend those data transfers and bring its processing activities into compliance with the GDPR.

TikTok initiated a statutory appeal against the DPC’s decision in the High Court under the Data Protection Act 2018.  Pending the outcome of that appeal, TikTok successfully applied to the High Court for a stay on the DPC’s decision.  The DPC appealed the grant of the stay to the Supreme Court.

The core legal issue before the Supreme Court was whether the test for granting such a stay is governed by Irish national procedural law, or by EU law.

What did the parties argue should be the legal test applicable to interim stays of regulatory decisions?

The DPC argued that the criteria for granting interim relief in this context should be governed by EU law and, in particular, by the approach adopted by the Court of Justice of the European Union (“CJEU“) in Zuckerfabrik Süderdithmarschen AG v Hauptzollamt Itzehoe and Zuckerfabrik Soest GmbH v Hauptzollamt Paderborn (EU:C:1991:65) (“Zuckerfabrik“).

The Zuckerfabrik test requires that:

• there are “serious doubts as to the validity of” the measure in question;
• a stay is required as a matter of urgency in the sense that it is necessary to avoid serious and irreversible damage to the party seeking the stay; and
• taking account of the interests of the EU, the urgency outweighs those interests and any other interests arising.

The DPC placed particular reliance on the “one-stop shop” mechanism established by the GDPR, noting that, by virtue of Article 60 GDPR, the lead supervisory authority cannot reach a final decision without the agreement of all supervisory authorities concerned.  On that basis, the DPC contended that the decision constitutes a joint action with other supervisory authorities, necessitating the application of EU procedural standards to ensure consistency and the full effectiveness of EU law.

TikTok, by contrast, argued that the domestic test, as set out in Okunade v. Minister for Justice [2012] IESC 49 (“Okunade”) (which dealt with decisions affecting specific individuals, such as deportation orders) should apply.  The Okunade case established the legal test and threshold for obtaining an interlocutory injunction or stay on a public administrative decision pending judicial review as follows:

• an application must establish an arguable case;
• the court must weigh the potential irreparable harm to the applicant against the public interest in the orderly implementation of lawful public measures; and
• there is a strong initial presumption in favour of the validity and implementation of administrative decisions.

Tiktok argued that implementing the suspension order would cause unprecedented, irrecoverable operational and financial damage, including potential irrecoverable financial losses exceeding €1 billion and the forced relocation of thousands of employees.

The Supreme Court’s decision – a new seven part framework to be applied to regulatory decisions with general public impact

Delivering the lead judgment for the Supreme Court, Mr Justice Murray held that the applicable test is one of national rather than EU procedural law.

The Court noted that the DPC is vested by statute with primary responsibility of determining how the data protection rights of EU citizens ought to be protected within the framework of the GDPR.  The courts should be slow to overturn the determinations of a regulatory body who is vested with such decision-making powers.

The Court retained the core balancing principles of Okunade but raised the initial threshold from an “arguable case” to a “strong case” in order to take account of the collective rights of third-party users affected by regulatory suspensions. Okunade was distinguished as the administrative decision under review in that case only directly affected one or a small number of persons, whereas the regulatory decision in this case was of more general effect, potentially affecting the rights and interests of many of TikTok’s users, whose fundamental rights in the protection of their personal data could be impacted by the DPC’s decision and the suspension of that decision.

The Court held that the following seven-part framework should be applied when considering whether to grant a stay of a regulator’s decision that has a broad impact on third party rights:

1. no stay will be granted unless the applicant / appellant establishes a stateable case;
2. save in the most unusual circumstances (indeed if ever), a stay requires the applicant / appellant to establish a strong case (ie, a ground that is “sufficiently clear and weighty that is likely to succeed at trial”);
3. where the applicant / appellant has a realistic prospect of recovering damages for losses caused by a decision that is ultimately quashed, and where there are reasonable grounds that the harm caused by the decision can be substantially reduced to a claim for damages, a stay should rarely be granted, and an applicant should be left to their remedy in damages;
4. in the absence of any basis for such a damages claim, the court should not consider whether the harm caused by the challenged order is capable of calculation or determination;
5. the court must balance the irreparable harm caused to the applicant / appellant if a stay is not imposed and they prevail in their claim against the damage to the public interest in the administration of the relevant regulatory statutory scheme if the stay is granted. This involves clear identification of (a) the specific harm alleged to arise to the applicant if the stay is not granted, and (b) the particular damage to the public interest in general, or third party rights if the stay is granted;
6. in considering the public interest in the administration of the statutory scheme in question, where the statutory scheme is intended to protect rights and interests of service users, or indeed the public, a stay should rarely issue if to do so would jeopardise those protections;
7. irrecoverable expense incurred in complying with a regulatory decision, even one eventually quashed on review or appeal, is a cost of conducting business in regulated sectors. A stay will not follow merely because compliance with the decision will result in irrecoverable financial loss. Something “significantly more” is required, such as a clear and substantial disproportion between the cost to and impact on the applicant / appellant if the decision is not stayed, and the impact on the public interest reflected in the decision if it is.

The Court went on to find that this national test fully respects the EU principles of equivalence and effectiveness and does not materially differ from the Zuckerfabrik approach.

The Court further clarified that, notwithstanding the GDPR’s one-stop shop mechanism, the DPC acting as lead supervisory authority is the sole maker of the final legally binding decision. Whilst the cooperation procedure under Article 60 GDPR requires engagement with other supervisory authorities, this does not transform the DPC’s decision into a joint act of multiple authorities so as to displace the application of national procedural law.

Why did the Supreme Court not make a preliminary reference to the CJEU?

The DPC had requested that a preliminary reference be made to the CJEU if the Supreme Court disagreed with its position on the applicability of the Zuckerfabrik test and EU law.  However, the Supreme Court declined to make a preliminary reference, noting that the substantive statutory appeal had already been heard by the High Court (in March 2026) and that judgment was awaited.  On that basis, any questions regarding the interlocutory stay would soon be overtaken by events.  (The High Court’s decision has since been delivered in two judgments available here and here).

How did the Supreme Court apply the new stay test in TikTok v DPC?

Even though the question of whether a “strong case” (i.e., one that is “sufficiently clear and weighty that is likely to succeed at trial”) had been established by TikTok was an open one, the fact the substantive statutory hearing had already concluded effectively rendered the stay application moot.  However, without expressing a view on the first limb of whether a strong case had been established, Mr Justice Murray concluded that, had a strong case been made out, in his view the High Court would have been justified in granting a stay because:

• the DPC’s decision would not take effect for six months, by which time the oral hearing of the appeal had actually concluded;
• the risks to TikTok users in this case were not significant; and
• the impact of not granting a stay was “immense”, extending not just to financial loss or inconvenience but also to material operational disruption if the DPC’s decision was to be immediately enforced and subsequently overturned.

Ultimately, the Supreme Court concluded that the balance of convenience in this case heavily favoured TikTok.  The Court dismissed the DPC’s appeal and maintained the stay on the DPC’s suspension and compliance orders until the DPC should choose to revisit the matter before the High Court.

What are the key takeaways for businesses in regulated sectors?

• Irish national procedural law governs the granting of interim stays on decisions of national regulatory bodies (such as those of the DPC) even where the applicable legislation requires engagement with other EU supervisory authorities.
• preliminary references to the CJEU will not be made where matters referred to the CJEU are likely to be overtaken by events in the national court.
• the initial threshold for seeking a stay on a decision of a regulatory body that has wider public impact is not an “arguable” case, but a “strong case”, being one that is “sufficiently clear and weighty that is likely to succeed at trial”. This means that it is more difficult to obtain a stay on such regulatory decisions.
• the seven-part framework set out by the Supreme Court in this case will need to be applied by all national courts going forward when considering whether to grant a stay on a regulatory decisions by bodies like the DPC, which often impact the fundamental rights of a wide third-party user base.
• even where a strong case has been established, it is not guaranteed that a stay will be granted as the court will then go on to consider the balance of convenience, balancing the potential impact on affected parties (including the public interest), as detailed in the seven-part framework.
• the Supreme Court considered irrecoverable expense incurred in complying with a regulatory decision, even one eventually quashed on review or appeal, to be a cost of conducting business in regulated sectors and a stay will not follow merely because compliance will result in irrecoverable financial loss.
• a challenge that is merely arguable will no longer stop the clock for compliance with decisions of regulators that impact the rights of a vast public user base.

Contact us

If you would like to discuss any of the matters addressed above, please contact Disputes and Investigations partners, Michael Byrne, Connor Cassidy, Karen Reynolds, Julie Murphy-O’Connor, April McClements, Aishlinn Gannon or your usual Matheson contact.