The Strategic Environmental Assessment Directive (Directive 2001/42/EC) (SEA) has been a lurking legal presence in EU and UK environmental law. Plainly of considerable significance in relation to strategic governmental plans and programmes, its practical implications are only now just beginning to be worked through. Legal challenges to decisions made even at the highest policy level are being brought on the back of the SEA Directive. This book is a comprehensive analysis of all aspects of the Directive, from its history and scope, to its impact on governmental policy and its implications in practice. The book is both timely, in light of key cases such as Case C-567/10 Inter-Environnement Bruxelles (CJEU, 22 March 2012) and HS2, and forward-looking, as it considers and projects future legal implications of the SEA Directive. Written by a blend of distinguished academics and leading practitioners it provides an in depth critique and rounded appreciation of both the immediate practical effects of SEA and its wider impact on European and UK environmental law.