ISTANBUL (AP) — Turkish politicians held their final rallies on the last hours of campaigning before Saturday, the eve of pivotal presidential and parliamentary elections that could significantly shape the NATO member’s future, before a so-called propaganda ban went into effect.

President Recep Tayyip Erdogan, who is facing the toughest challenge ever in his two decades of power, spoke at three neighborhood rallies in Istanbul, Turkey’s biggest city.

His main challenger is Kemal Kilicdaroglu of the pro-secular, center-left CHP (the Republican People’s Party), who is the joint candidate of six opposition parties. He held his final rally in the capital, Ankara, on Friday in the pouring rain. On Saturday, he and some of his supporters visited the mausoleum of Mustafa Kemal Ataturk, the founder of modern Turkey and of the CHP.

On Friday, Erdogan dismissed speculation that he wouldn’t cede power if he lost, calling the question “very ridiculous.” In an interview with more than a dozen Turkish broadcasters, Erdogan said he came to power through democracy and would act in line with the democratic process.

“If our nation decides to make such a different decision, we will do exactly what’s required by democracy and there’s nothing else to do,” he said.

Erdogan said Saturday that he viewed the elections as a “celebration of democracy for our country’s future.” He showcased his government’s defense and infrastructure investments and aired videos trying to undermine his opponent as incapable of leading Turkey, while claiming he was colluding with terror groups. He also argued the opposition was pro-LGBTQ and therefore anti-family in a now regular targeting of LGBTQ people in Turkey.

The opposition’s campaign was continued by Istanbul’s popular mayor, Ekrem Imamoglu, who held final rallies in the city to call on people to vote for Kilicdaroglu. As in previous elections, mainstream media coverage of campaign events remained unequal, with Erdogan’s rallies getting constant live airtime.

On Friday, Kilicdaroglu asked tens of thousands gathered to hear his final speech to go vote on Sunday to “change Turkey’s destiny.” He said he was ready to bring democracy to Turkey, a major criticism of Erdogan who has cracked down on dissent in recent years and concentrated most powers of the state in his hands.

“We will show the whole world that our beautiful country is one that can bring democracy through democratic means,” he said. Though Kilicdaroglu and his party have lost all past presidential and parliamentary elections since he took the helm of the party in 2010, opinion polls have showed he has a slight lead over Erdogan.

Voter turnout in Turkey is traditionally strong, showing continued belief in this type of civic participation in a country where freedom of expression and assembly have been suppressed.

If no presidential candidate secures more than 50% of the vote, a runoff election will be held on May 28. Turkey will also be electing parliamentarians to its 600-seat assembly Sunday.

Turkey’s Supreme Electoral Board said it decided that votes cast for another presidential candidate, Muharrem Ince, who pulled out of the race this week would be counted as valid and that his withdrawal would not be considered until a potential second round. Analysts had predicted Ince voters would shift to Kilicdaroglu.