The High Court has referred questions about Dublin Airport’s passenger and slot limits to the Court of Justice of the European Union (CJEU), pausing six judicial review cases until the EU court responds.
In a ruling delivered on 11 December 2024, Mr Justice Barry O’Donnell said the cases challenge Irish Aviation Authority (IAA) decisions setting coordination parameters for Dublin Airport for Winter 2024/25 and Summer 2025. Those decisions included seasonal Passenger Air Traffic Movement seat caps, based on planning conditions limiting the combined capacity of Terminals 1 and 2 to 32 million passengers a year unless further permission is granted.
Airlines argue that the conditions restrict passenger throughput rather than the airport’s capacity to accommodate flights, and that the IAA lacked power to use them to limit available slots. They also dispute whether the conditions qualify as relevant technical, operational or environmental constraints under EU slot-allocation rules. daa, the airport’s owner and operator, and the IAA argue that the planning conditions are binding constraints that must be considered when setting coordination parameters.
The cases also raise whether seasonal parameters may result in airlines receiving fewer historic slots than they would otherwise qualify for, and whether an airport management body may close an airport unilaterally to prevent allocated slots being used and avoid breaching an annual passenger limit. Airlines contend that historic slots carry protected statutory or property rights; the IAA disputes that position. These are submissions and questions for the EU court, not findings made in this ruling.
The High Court had scheduled a five-day hearing beginning on 3 December. After parties sought an early reference and reached agreement on proposed questions, the judge decided that EU guidance was necessary before the domestic cases could be resolved. He said an early reference would allow a more focused hearing and make efficient use of court and party resources.
The court referred three questions concerning the relevance of planning consents and passenger limits, possible non-allocation of historic slots, and unilateral airport closure. It adjourned all six judicial review proceedings pending the CJEU’s determination and reserved costs to date. The ruling does not decide whether the IAA acted lawfully or resolve the underlying challenges. The parties may apply on four days’ notice if an issue arises in the meantime.
Separately, a High Court stay granted on 4 November 2024 suspends the Summer 2025 passenger seat cap until the proceedings are determined or further order. The ruling says the stay allowed Airport Coordination Limited to allocate airlines all their historic slots for that season; the other elements of the Summer 2025 decision were unaffected.