Millions of Turks living abroad wrapped up voting on Tuesday, in a tense election that has turned into a referendum on President Recep Tayyip Erdogan’s polarising two-decade rule. Sunday’s presidential and parliamentary ballot will pass judgment on Turkey’s longest-serving leader and the social transformation spearheaded by his Islamic-rooted party. The vote is Turkey’s most consequential in generations and the toughest of the 69-year-old’s tectonic career. Polls show Erdogan locked in a tight battle with secular rival Kemal Kilicdaroglu and his powerful alliance of six parties that span Turkey’s cultural and political divide. The first votes were cast by Turks who moved from poorer provinces to Western Europe over the decades under job schemes aimed at combating the continent’s labour shortage in the wake of World War II. Such voters comprise 3.4 million of Turkey’s 64.1 million registered electorate and tend to support more conservative candidates. Official turnout on the morning of the last day of overseas voting on Tuesday was reported at 51 percent — a touch lower than in past elections and a possible sign of worry for Erdogan. “I am here because Turkey is in a quite terrible situation right now,” Berliner Kutay Yilmaz said on the first day of voting in Germany late last month. “I want to return (to Turkey) one day. That’s why I came here today and voted. I want the leader to change.”