European Union – Environment. The Court of Justice of the European Union made a preliminary ruling concerning the interpretation of arts 4 and 19 of the Treaty on the Functioning of the European Union and arts 13, 22, 23 and 30 of Directive (EC) 2008/50 of the European Parliament and of the Council (on ambient air quality and cleaner air for Europe). The request had been made in proceedings between ClientEarth, a non‑governmental organisation interested in protection of the environment, and the United Kingdom Secretary of State for the Environment, Food and Rural Affairs, concerning that organisation's request for revision of the air quality plans drawn up by the UK under Directive 2008/50 for certain of its zones and agglomerations.