Turkey’s leader Recep Tayyip Erdoğan and rival Kemal Kılıçdaroğlu were locked in a tight battle for the presidency on Monday morning as the election count suggested rising odds of an unprecedented second round.

Both Erdoğan and Kılıçdaroğlu, who leads a six-party opposition alliance, have claimed to be ahead in Sunday’s race and warned against drawing conclusions from the preliminary vote count. But neither side appeared to be in line to clinch the majority required to win the contest outright, suggesting that the presidential election would go to a run-off in two weeks’ time.

Erdoğan had secured just under 50 per cent of the vote, compared with 45 per cent for Kılıçdaroğlu, according to figures collated by the state-run Anadolu news agency, based on the count from 96 per cent of ballot boxes.

Erdoğan, who first carried the Justice and Development party (AKP) to power in 2002, faced his toughest campaign as he sparred with Kılıçdaroğlu in a race that both candidates portrayed as a battle for the future of Turkey.

Speaking to a large crowd at the AKP headquarters in Ankara at about 2am on Monday, Erdoğan conceded that the vote remained too close to call and could go to a second round for the first time since Turkey switched to an executive presidency in 2017.

“We know we’re ahead in the elections, but we’re waiting for the manifestation of the national will, as the result has not been officially seen yet,” Erdoğan said from a balcony at the AKP building.

Kılıçdaroğlu, standing with the other leaders of the opposition coalition, said shortly after the president spoke that “Erdoğan did not get the result he expected despite all his slander and insults”. He added that “the data continues to flow” and that should the elections go to a second round, “we will definitely win”.

The other candidate seeking the presidency, Sinan Oğan, who broke from the ultranationalist Nationalist Movement party, won about 5 per cent of the vote, according to Anadolu’s figures. His share is significant because the current level denies the main candidates the majority they need to win outright.

Polls in the lead-up to Sunday’s hotly contested election showed Kılıçdaroğlu had the edge over Erdoğan, but the margin of error led many analysts to forecast a runoff.

Erdoğan’s parliamentary alliance, which includes his AKP and the Nationalist Movement party, appeared set to hold on to its majority after Sunday’s election. The coalition had clinched 323 of the 600 seats, according to Anadolu’s figures, based on 96 per cent of the ballot boxes opened. The opposition alliance had 211.

In a sign of the high tensions, Kılıçdaroğlu’s allies objected on Sunday evening to data provided by Anadolu, arguing that the calculations excluded areas where the opposition had performed well and claimed the AKP was slowing down the counting process by raising objections in opposition strongholds.

“My advice is ignore Anadolu agency numbers because they are trying to deceive you,” Ekrem İmamoğlu, the Istanbul mayor who is one of the top leaders in the “table of six” coalition, said on Sunday.

AKP spokesperson Ömer Çelik defended Anadolu, saying it remained the main source for election reporting and that the “attacks” by Kılıçdaroğlu’s Republican People’s party (CHP) amounted to “propaganda”.

“Whatever the results of the election, we have a tradition of respecting the results. The tradition of not respecting the results with coups, memorandums and the tutelage of the judiciary is with you,” Çelik said of the CHP.

Polling centres had been busy across Turkey after more than 60mn people registered to vote in presidential and parliamentary elections that offered two widely divergent paths for Turkey.

Kılıçdaroğlu has vowed to revive Turkey’s ailing economy, bring the country closer to the west’s orbit and restore crucial institutions that have been undermined during Erdoğan’s long tenure, first as prime minister and then as president.

The 74-year-old opposition leader has regularly campaigned with other popular politicians who are part of the “table of six” coalition.

Erdoğan, whose final campaign stop on Saturday was attending evening prayers at the Hagia Sophia mosque in Istanbul, remains popular with conservative, pious voters in Turkey’s Anatolian heartland.

At fiery campaign rallies, Erdoğan framed himself as the only politician who could secure a prosperous future for Turkey and defend family values. On Saturday, he accused Kılıçdaroğlu of working with US president Joe Biden to defeat him, without presenting evidence.

Kılıçdaroğlu, meanwhile, called on voters to “change Turkey’s destiny” by voting for his opposition alliance.