Polish voters denied President Andrzej Duda’s bid for quick re-election, forcing him into a runoff that risks halting a nationalist makeover of the eastern European country.

The second-round ballot — which opinion polls suggest is too close to call — will decide whether the European Union’s largest formerly communist county will complete a five-year drive that has put it at odds with the bloc’s democratic and multicultural values.

Duda won 41.8 percent of Sunday’s ballot, followed by 30.4 percent for opposition candidate and Warsaw Mayor Rafal Trzaskowski, according to an exit poll for Poland’s three main television broadcasters. If the results are confirmed, the two will square off in a final ballot on July 12.