This book explores the modes of European Union (EU) contestation which are mobilized by radical parties and seeks to unearth the relationship of such contestation with populist discourses. It looks specifically at how rightist and leftist parties articulate populist discourses with representations and problematizations of Europe and the EU by examining the left-wing Podemos in Spain and the right-wing Alternative für Deutschland (AfD) in Germany. It argues that radical parties also build their Euroscepticism on other hegemonic discourses and populism is only one possible discursive articulation to mobilize the contestation of the EU. It examines whether populism discourses may serve (or not) as a stimulus for EU contestation and as such shows the implications that this may have for the persistence of Euroscepticism in Western European democracies. This book will be of key interest to scholars and students of radical parties, democracy, democratic and political theory, populism, Euroscepticism, discourse studies and more broadly to comparative politics and European studies.