President Rumen Radev's recent statement that 18 of the 27 EU member states held referendums on their accession under the condition of adopting the euro does not hold up against the facts. The claim was made during an interview with CNN on June 11, 2025, and later published on the official website of the Bulgarian Presidency.

In reality, only 16 EU member states have held referendums related to the Maastricht Treaty - the legal basis that sets out the obligation for EU countries to adopt the common European currency. This treaty, adopted in 1993, introduced the Economic and Monetary Union, which includes the requirement to eventually adopt the euro. Any country joining the EU after 1993 automatically agreed to these terms upon accession.

Out of the 16 countries that have become EU members since 1993, 13 organized referendums on their accession under the Maastricht framework. These nations include Austria, Finland, Sweden, Slovenia, Slovakia, Estonia, Latvia, Lithuania, Malta, the Czech Republic, Poland, Hungary, and Croatia. Meanwhile, three other countries - Cyprus, Romania, and Bulgaria - ratified the treaty and accepted the euro obligation without holding a national referendum on EU accession.

Eight older member states - Germany, the Netherlands, Belgium, Italy, Spain, Portugal, Greece, and Luxembourg - were already in the EU prior to 1993 and accepted the Maastricht Treaty without putting it to a public vote. These countries adopted the treaty and the related euro commitment through parliamentary ratification.

In addition, France, Ireland, and Denmark also held referendums on the Maastricht Treaty in the early 1990s. However, these were not referendums on EU accession, as these countries were already members at the time - France as a founding state, and Ireland and Denmark since 1973. Their referendums were specifically about accepting the new terms laid out in the treaty, including provisions on the common currency. While France and Ireland approved the treaty, Denmark initially voted against it. Following this rejection, Denmark secured four opt-outs from various treaty obligations, including the euro, and held a second referendum where voters approved the treaty with the exceptions in place.

In summary, only 16 EU countries have held referendums connected to the Maastricht Treaty and its euro-related commitments. Of those, 13 did so during their accession process. This directly contradicts President Radev's claim, as it shows that 11 of the current 27 member states have never submitted the Maastricht Treaty - and the euro obligation within it?to a referendum.

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