Sarah Macky Partner at Heaney & Partners discusses the circumstances in which courts may permit representative proceedings in negligence claims against public bodies.
The recent High Court decision of McConnachie & Ors v Bay of Plenty Regional Council [2026] NZHC 836 concerned an application to bring a representative (class) action against the Bay of Plenty Regional Council in relation to alleged negligence.
It was alleged the Council’s negligence caused numerous properties to suffer flood damage resulting from the Edgecumbe flood on 6 April 2017. Heaney & Partners acted for the Council in successfully defending the plaintiffs’ application to bring a representative action.
This case explores the circumstances in which courts may permit representative proceedings in negligence claims against public bodies, and the implications this has for exposure to large-scale liability.
At the core of the decision is whether the plaintiffs met the legal threshold to proceed as a representative action under High Court rules. Representative actions allow one or more plaintiffs to sue on behalf of a wider group where those individuals share the “same interest” in the subject matter of the proceeding.
The Court emphasised that this requirement is not merely procedural but fundamental. It ensures fairness to both plaintiffs and defendants, particularly where liability and damages may vary across the represented class.
The plaintiffs alleged that the Council had breached duties relating to environmental management and flood protection, or similar regulatory responsibilities, and that these failures caused widespread harm. They argued that the issues of duty and breach were common across all class members, justifying a representative proceeding. In opposing the application, the Council contended that individual circumstances, such as differing property characteristics, causation issues, and quantum of loss, meant that the claims did not share sufficient commonality.
The Court undertook a detailed analysis of the “same interest” test. It confirmed that while some variation between class members is permissible, there must be a significant level of commonality in the legal and factual issues.
The Court distinguished between truly common issues, such as whether a duty of care exists in principle, and issues requiring individualised assessment such as causation and damages. Importantly, the Court reiterated that negligence claims, particularly against local authorities, often involve highly fact-specific inquiries, which can complicate attempts to proceed on a representative basis.
A key aspect of the judgment is the Court’s cautious approach to allowing representative actions in negligence against public bodies. While not ruling out such claims entirely, the Court signalled that they should be scrutinised carefully. The Court recognised that public authorities operate in complex regulatory environments, often balancing competing statutory obligations, resource constraints, and policy considerations. The Court acknowledged that imposing broad, collective liability through representative actions could have significant implications for public administration and funding.
The Court ultimately assessed whether the common issues identified by the plaintiffs were sufficiently central to justify a representative proceeding. It examined whether resolving those issues would materially advance the claims of all class members, or whether the proceeding would become focused on numerous individual inquiries.
In doing so, the Court considered procedural fairness, efficiency, and the risk of prejudice to the Council.
While aspects of the claim may have satisfied the threshold for commonality, the Court expressed concern about the manageability of the proceeding. It noted that where individual issues dominate, particularly in negligence cases involving causation and loss, it may be inappropriate to proceed on a representative basis.
The Court also highlighted the importance of defining the class clearly and ensuring that membership can be determined objectively.
The decision is notable for the following reasons.
Representative actions are being considered more often as a method of pursuing claims against public authorities. Even where such claims ultimately face hurdles, the procedural step of seeking approval to proceed representatively can expose councils to significant litigation risk, reputational impact, and legal costs.
The Court’s analysis demonstrates that negligence claims against councils are not easily suited to representative treatment. The variability of factual circumstances, such as differences in property location, exposure to risk, and individual loss, can undermine the “same interest” requirement. This does provide some protection to local authorities in preventing representative actions being pursued.
However, the decision should not be taken as eliminating the risk. The Court did not establish a blanket prohibition on representative negligence claims against local authorities.
Instead, it confirmed that each case will turn on its facts. Where plaintiffs can frame their claims around genuinely common issues, particularly at the level of duty and systemic failure, courts may be willing to allow representative proceedings, at least in part.
The judgment highlights the importance of robust decision making and documentation by councils. Where allegations of systemic negligence arise, the ability to demonstrate compliance with statutory duties, adherence to standards, and reasoned decision-making processes is important.
In conclusion, the High Court’s decision reflects a cautious but open approach to representative negligence claims against local authorities. While the “same interest” requirement provides a significant safeguard, it does not preclude such claims entirely.