ISTANBUL—Turkey’s opposition looked poised to win control of the country’s two biggest cities Monday as it dealt President Recep Tayyip Erdogan’s Justice and Development Party, or AK Parti, one of its most serious electoral setbacks in years. The opposition won Ankara, a ruling party stronghold for decades, and was leading a tight race for mayor in Istanbul, according to unofficial figures Monday.
The leader who has dominated Turkish politics for 16 years declared victory despite the opposition gains.
