EU Court Rules Dublin Airport's 32-Million Passenger Cap Must Be Considered in Slot Allocation
Why It MattersLegally binding planning limits can now constrain slot allocation at congested EU airports, which may force carriers to give up historical slots wherever such caps bind.
The Court of Justice of the European Union ruled on 15 October 2026, in Case C-857/24 (daa and Others), that regulators must take Dublin Airport's 32-million-passenger annual limit into account when allocating airline take-off and landing slots. The case involved airport operator daa, the Irish Aviation Authority (IAA) and several airlines. It arose after airlines challenged the IAA's decision to include the cap when setting the terms for slot allocation for winter 2024, and an Irish High Court judge referred questions to the CJEU in December 2024.
The CJEU clarified that capacity constraints under EU slot rules can include legally binding planning restrictions, not only physical infrastructure limits. It also held that where such a restriction limits available slots, airlines may exceptionally be prevented from retaining some historical slots or parts of their slot series. The cap was set in planning permissions for Terminal 2 and the Terminal 1 extension in 2007 and 2008. Dublin handled 36.4 million passengers in 2025, about 4.4 million above the limit, and expects to exceed that number this year. In February 2026, Advocate General Manuel Campos Sánchez-Bordona gave an opinion supporting the IAA's position.
The ruling does not affect the IAA's recent decision to add 28 new take-off and landing slots at Dublin for next summer, and it does not itself prevent the Irish government from changing the cap. The Dublin Airport (Passenger Capacity) Act, passed this summer, allows the Minister for Transport to increase or revoke the cap. In August, daa formally asked Minister Darragh O'Brien to raise it to 40 million, which started the process required by the law, and daa has also applied to Fingal County Council for planning permission to expand the airport.
Daa said the ruling brought "much-needed clarity". Aer Lingus said the capacity act had overtaken the CJEU ruling and called for the remaining statutory process to be completed quickly. Ryanair chief executive Michael O'Leary said the ruling showed the need to abolish the cap and predicted Dublin traffic would reach 40 million next year. The High Court adjourned the airlines' challenge after the referral, and the Irish courts must apply the CJEU ruling if the airlines continue their original action.
