The ruling Justice and Development (AK) Party will appeal to the top election authority for recount of votes cast in all districts of Istanbul, a party official said on Sunday.
Speaking to reporters in Istanbul, Justice and Development (AK) Party Deputy Chairman Ali Ihsan Yavuz said: "Only 70% of the invalid votes have been counted so far."
"There is organized irregularity, organized abuse here. They are beyond errors," he added.
According to unofficial results, the main opposition Republican People's Party (CHP) candidate Ekrem Imamoğlu leads Istanbul with 48.79% of the votes, whereas Binali Yıldırım of AK Party follows with 48.51% of the votes.
However, the AK Party has said a recount might change the results.
Millions of Turkish voters cast their votes nationwide last Sunday in the local elections to choose Turkey's mayors, city council members, mukhtars (neighborhood officials), and members of elder councils for the next five years.
According to unofficial results, the AK Party is leading in 15 metropolitan municipalities (larger cities) and 24 smaller cities.
