'Ever since the Lisbon Treaty introduced both delegated and implementing acts into the EU's legal system, observers and practitioners alike have debated the nature and the implications of the choice between these different instruments. This authoritative book sheds light on the many intricacies of this 'labyrinth', making it a compelling read for anyone seeking a better understanding of delegated rule-making in the European Union.'--Thomas Christiansen, Maastricht University, the Netherlands'The choice between delegated and implementing acts is one of the most important innovations brought by the Lisbon Treaty and still poses many complex constitutional questions. This book offers an insightful and provocative re-evaluation of these questions in their theoretical, jurisprudential and practical contexts; and it will, as such, be of great interest to all students of the Union's executive law-making powers.'--Robert Schütze, Durham University, UK and College of Europe, Bruges, Belgium'Articles 290 and 291 TFEU were designed to provide a clear framework for the EU's subordinate legislation. Clarity, however, was lost between the Constitution for Europe and the Treaty of Lisbon. Tauschinsky and Weiß collected very thorough analyses to answer the manifold questions of differentiation between delegated and implementing legislation.'--Matthias Ruffert, Humboldt-Universität zu Berlin, Germany