Opposition leads in Istanbul, state media acknowledges
While official results from the Supreme Electoral Authority (YSK) are yet to be published, YSK chief Sadi Guven said earlier on Monday People's Republican Party (CHP) candidate Ekrem Imamoglu was in the lead by almost 28,000 votes, with only 80 ballot boxes left to be counted.
"There are 16 [uncounted] ballot boxes left. My lead is by 25,158 votes. I would like to thank the Supreme Election Council for sharing the results," Imamoglu announced later on Monday.
The CHP politician, who has now declared himself mayor of Istanbul, has pledged to serve all residents of the metropolis equally, no matter their political affiliation, ethnicity or religious creed.
Turkish state news agency Anadolu had earlier paused updating its unofficial results for hours, causing complaint by opposition voices who claimed the hours-long pause in the count was political manipulation.
Those results had put former prime minister and ruling Justice and Development Party (AKP) candidate Binali Yildirim, who claimed he had won the mayorship on Sunday night, in the lead.
Anadolu updated its count of the vote mid-afternoon to put Imamoglu in the lead with 50.9 percent of the vote and Yildirim in second place with 47.1 percent, with 99.8 percent of the ballots counted.
While the CHP appears to have won Istanbul, as well as its coastal stronghold Izmir and the capital Ankara, the AKP retains control of the majority of Istanbul's internal districts.
However, the apparent loss of Turkey's three biggest and most politically significant cities represents a blow to President Recep Tayyip Erdogan's government in an election which has been seen to be the most important test yet for his executive presidency.
The Istanbul mayorship is particularly significant as it was in this position that in 1994 Erdogan began his climb up the political ladder towards being elected as a near-all-powerful president in 2018.
It is also a position which, similarly to the Ankara mayorship, has been held by the AKP and its predecessor the Welfare Party (RP) since 1994.
"As of now the CHP candidate has more votes than us," Yildirim acknowledged on Monday afternoon.
However, the former prime minister claimed that there are 216,000 invalid votes which will need to be assessed.
The AKP plans to contest "voting irregularities" in Ankara, Istanbul and Igdir, where the pro-Kurdish HDP beat the AKP and two nationalist parties, according to Daily Sabah.
Complaints by an parties are likely to take days to resolve, so a final official tally by the YSK may not be apparent for some time.