Both Turkish election rivals claim early leads, but a runoff is likely

• Polls point to tight contest
• Erdogan's 20-year rule on the line
• Sources from both camps say May 28 runoff likely

The parties of Tayyip Erdogan and Kemal Kilicdaroglu, the opposition candidate, each appeared to be headed for a runoff in Turkey's presidential election, while sources in both camps acknowledged they might not reach the required 50% of the vote to win outright.

Erdogan led by a wide margin in the early returns on Sunday, but as the count went on, his lead shrank as was to be predicted. A May 28 runoff seemed imminent, delaying the outcome of the president's 20 years in office.

Kilicdaroglu, the leader of a six-party coalition, held a modest advantage in polls conducted prior to the election, and two on Friday even put him above the 50% mark. However, the majority had predicted a slim margin.

Neither side declared a winner after rejecting the other side's count.

Erdogan advised poll officials to record all national results on Sunday, while Kilicdaroglu warned against hastily announcing election results while the counting is still ongoing.

There appears to be no winner in the first round, according to a senior official from the opposition alliance. But according to our data, Kilicdaroglu will take the lead.