“The Supreme Court has taken the UK’s lack of compliance with EU legislation, Directive 2008/50 (limiting the amount of nitrogen dioxide in air) much more seriously than the courts below. It has made a declaration that the UK is in breach and has referred questions of interpretation concerning the Directive and remedies to the CJEU.”
UK Human Rights Blog, 1st May 2013
Source: www.ukhumanrightsblog.com