SOFIA, Bulgaria — Bulgaria is close to realizing its decades-old goal of joining the euro currency union and deepening ties with the more prosperous countries of Western Europe. But the government faces a populist backlash against the shared currency on the eve of a key decision by European Union authorities.

The European Union gave Bulgaria the green light to join the euro, but political ructions in Sofia threaten to torpedo its accession.

Bulgaria has gotten the all-clear from two key European Union institutions to adopt the euro in January 2026. The bloc’s executive arm, the European Commission, and the European Central Bank said in separate reports that all the requirements on issues including inflation and public debt have been fulfilled.