President Recep Tayyip Erdogan's ruling party is leading in municipal elections that he has depicted as a fight for Turkey's survival, but may lose control of the capital in the vote that is seen as a test of his support amid a sharp economic downturn.
Erdogan's conservative, Islamic-based party gained 46 per cent of the votes in the elections with more than half of the more than 194,000 ballot boxes counted, according to state broadcaster TRT.
The main, secular-oriented opposition party has 30.5 per cent.
However, the opposition is leading in Ankara with 49.5 per cent of the votes, according to TRT, in a setback for Erdogan whose ruling party and its predecessor have held the mayoral seat for 25 years.
Erdogan's party appeared to be still holding Istanbul, the country's commercial hub, although the opposition's candidate narrowed the gap.