One possible explanation for the European sovereign debt crises is that the European Economic and Monetary Union (EMU) gave rise to consolidation fatigue or even deliberate over‐borrowing. This paper explores the validity of this explanation by studying how three decisive stages in the history of the EMU affected public borrowing in EU member states: the signing of the Maastricht Treaty, the introduction of the Euro, and the suspension of the Stability and Growth Pact (SGP). The methodology relies on difference‐in‐difference regressions for 26 OECD countries over the 1975–2009 period. The findings indicate that the Maastricht treaty reduced deficits especially in traditionally high‐deficit countries. In contrast, the introduction of the Euro and the watering down of the original SGP led on average to higher borrowing. These results indicate that the introduction of the Euro and the suspension of the SGP led to soft budget constraints in the EMU.