The author analyzes the Polish 2003 EU membership referendum. In the first part of the paper she looks into the factors which influenced the evolution of individual political actors in the course of the European debate in Poland. Due to the increasing interest in the significance of the EU-related issues for the consolidation of the political system in Poland, the first part of the paper focuses on the EU-membership debate and on the role of the political elite and the public support. In the second part the author analyzes the role of the referendum in that debate and its impact on the political actors’ strategy. The author analyzes the mobilization of the pro-European and the anti-European camp.