Mark Gibson and Paola Sproul

In McKenzie v Covidien LP [2026] CSOH 48, Lady Haldane granted both permission to bring group proceedings and authorisation of the representative party on behalf of 83 hernia mesh claimants. One month later, in Donnelly v Johnson & Johnson Medical Limited [2026] CSIH 32, the Inner House of the Court of Session refused an appeal against this only refusal of permission to bring group proceedings yet pronounced under the Civil Litigation (Expenses and Group Proceedings) (Scotland) Act 2018.

Recap on Donnelly

The scope of Donnelly has been widely overstated. In the decision at first instance ([2025] CSOH 77), Lord Young was dealing with 18 claims by 17 claimants across five different hernia mesh products. He found that the claimants had prima facie claims with real prospects of success, and he accepted that there were common factual issues. Permission was refused on one ground only, the requirement in rule 26A.11(5)(c) of the rules of Court of Session (rules) to demonstrate that group proceedings would be a more efficient administration of justice than separate individual actions. That single ground was the whole focus of the appeal. The Appeal Court named it the “superiority requirement” adopting the term used in other class action regimes.

Superiority requirement

The Appeal Court refused the appeal in Donnelly in their opinion of 23 June 2026 CSIH 32. The decision on permission was discretionary, and the test for appellate interference, as set out in Mackay v Nissan Motor Co Ltd [2025] CSIH 14 and Forsyth v AF Stoddard & Co Ltd 1985 SLT 51, is a high one. The lord ordinary had examined the issues arising in the particular claims, compared how they might be managed under each route, and had given reasons. That was enough.

The reasoning behind that conclusion is more helpful to applicants than the disposal suggests. The Appeal Court held that a low number of group members does not of itself defeat the requirement, since Parliament expressly set the minimum group at two, and a claim suitable for a large group does not necessarily become unsuitable when the group is small. More significantly, it identified a close connection between superiority and the statutory commonality test in section 20(6)(a) of the Act. Where there is commonality among issues, it is usually more efficient to resolve the claims together in a single group proceeding. The court left open the possibility that particular circumstances might point the other way, but that appears to be the default direction of travel.

The opinion also sets out, at some length, what group procedure is for. It avoids multiple summonses, multiple motions, and multiple hearings; it avoids claims being split between the sheriff court and the Court of Session according to value, and it avoids the same product being litigated in sheriff courts across the country. Case management under Chapter 26A is broader and more flexible than the traditional methods of handling related actions. The lord ordinary can order disclosure without recourse to commission and diligence, can restrict pleadings to particular issues, can direct parties to focus first on a declarator of liability and postpone individual circumstances and losses, and need not identify a test case at all.

Case management, the court added, is not a matter for the permission stage. It belongs at the preliminary hearing and the case management hearing fixed under the rules, by which point defences have been lodged and the court can see what is genuinely in dispute.

The drafting lesson

The group proceedings practice note requires an application to address the permission tests, including superiority, in detailed averments. Two factors relied on in the appeal – the exclusive jurisdiction of the sheriff court over lower-value claims and the risk that individual claims would become time-barred – were absent from the application. The lord ordinary could not be expected to consider matters that had not been put before him.

Competency point

Practitioners should note the court’s treatment of leave to appeal. The rules appear to require leave for an appeal against an authorisation decision, and that was the assumption on which leave was sought and refused in Bridgehouse v Bayerische Motoren Werke [2024] CSOH 16. The Extra Division held otherwise. Each application for permission and for authorisation is a stand-alone proceeding with its own case number, so a decision on authorisation disposes of the whole subject matter of that proceeding and may be appealed against without leave. The appeal motion on authorisation was therefore competent even though leave had never been sought.

Deliberately flexible test

Against that background, the most quotable passage in McKenzie is likely to be cited regularly. Lady Haldane held that the permission test under the 2018 Act is “deliberately flexible and non-prescriptive”, consistent with the public policy aim of increasing access to justice. Parliament had not excluded medical device litigation of this kind from the scope of group proceedings, and product or patient level differences were for case management once proceedings were underway rather than a gateway issue.

On commonality, she held that the statutory test asks whether the proceedings raise issues that are the same, similar or related, not identical. The 83 group members had different mesh products implanted for different types of hernia, but all were manufactured by the respondent, and common questions arose about the risks of mesh implantation generally, the amount of mesh used and what was known about possible complications. Those issues could be examined through substantially the same evidence. Covidien’s counsel had argued that the variation in products and in limitation positions was a fundamental problem for collective treatment, in terms that echoed the successful argument in Donnelly. It did not succeed a second time.

Practice points

For applicants, McKenzie is now the natural authority wherever a defender raises product or patient level heterogeneity as an objection to commonality. Donnelly has supplied the complementary point on efficiency. A shared manufacturer and a shared category of generic issue may be enough, and where commonality is established the superiority requirement will normally follow. However, superiority should also be addressed in the application itself with the specific practical benefits and the jurisdictional and limitation consequences of the alternative.

For defenders, the appeal confirms that Donnelly remains a decision on its own facts, an underdeveloped proposal and a relatively small group. It also confirms that a refusal of permission, once properly reasoned, is very difficult to disturb. Resisting permission on the basis of differences between group members will require more than pointing to those differences in the abstract.

Conclusion

Taken together these two decisions show the court is applying a deliberately flexible approach to the permission stage with growing confidence while confirming that the statutory and procedural requirements must still be substantively addressed. Several broader questions remain unresolved as the regime develops: whether Scotland will move to an opt-out model, how the requirement for the representative party to consult group members before settlement will operate, and how substantive case management will be handled once proceedings are underway? Neither McKenzie nor the Donnelly appeal answers those questions: their resolution remains to be seen.

Mark Gibson is a partner and Paola Sproul is a senior solicitor at Digby Brown LLP