This book provides the first comprehensive study of how the COVID-19 pandemic and the war in Ukraine reshaped party-based Euroscepticism in the 2019–2024 European Parliament. It applies natural language processing (NLP) techniques to multilingual Twitter data to examine how Eurosceptic parties responded to the EU's handling of these crises. Moving beyond conventional analyses based on party manifestos and expert surveys, it tracks changes in issue salience and party positions at two-month intervals, offering a more detailed account of evolving Eurosceptic discourse. Drawing on tweets from 16 Eurosceptic parties on both the left and the right across nine EU member states, it demonstrates how the nature of each crisis set the discursive agenda, while ideological orientation and national context shaped party positioning and Eurosceptic framing. The book finds that party-based Euroscepticism is not only heterogeneous but also pragmatic, contesting some crisis measures while accommodating, or even endorsing, others. It will be of interest to scholars and students of European politics, political communication, and comparative politics.

Gilsun Jeong is Teaching Associate in Politics at the University of Nottingham, UK,  where he teaches comparative politics and European politics, alongside research on student engagement with AI in higher education and its policy implications. Previously, he served as a Research Associate in Politics and Artificial Intelligence on the RAI UK project, Harnessing AI to Enhance Electoral Oversight. His research interests include European party politics, Euroscepticism, democratic governance, and the sociopolitical implications of artificial intelligence.