R (on the application of ClientEarth) v Secretary of State for Environment, Food and Rural Affairs

Air pollution – Directive 2008/50/EC – Limits on nitrogen dioxide levels in outdoor air – UK not complying with mandatory limits by deadline imposed by directive – Air quality plans drafted in connection with applications for time extension under articles 22 and 23 – Whether appellant entitled to declaration of non-compliance with article 13 – Declaration granted – Questions referred to Court of Justice of European Union