The Court has today confirmed that airport slots can be reduced under the EU Slot Regulation if there are constraints put in place, such as an annual passenger limit.

The aviation industry has long claimed that governments could not reduce slots at airports. Today’s ruling proves that to be incorrect and opens the door for governments to use slot allocation as a tool to reduce aviation’s climate impacts.

This ruling aligns with Opportunity Green’s legal analysis and the expert opinion on these questions in October 2025. The analysis also showed that broader climate-related measures, such as national carbon budgets, should also be relevant constraints if they affect airport infrastructure.

“This ruling is an important step towards ensuring that airport capacity decisions are consistent with governments’ legal obligations.” Olivia Moyle, Legal Officer at Opportunity Green, says. “For too long, the aviation industry has argued that restrictions on airport capacity cannot be reflected in slot allocation. The Court’s decision provides much-needed clarity and reinforces the need to consider the legal constraints that apply to airports. Governments must now make full use of the legal tools available to address aviation’s climate impacts.”

The EU Slot Regulation provides Member States with general rules on airport slot allocation and reduction. Under consideration by the CJEU were three questions posed by the Irish High Court. These looked at whether the interpretation of ‘constraints’ that are considered when allocating annual airline slots extends to legal constraints placed on an airport.

Read more in the article of T&E