Turkey's presidential election is underway, with President Tayyip Erdogan facing his toughest political challenge in 20 years of rule. Here's everything you need to know

about the election, the candidates, and the key issues at stake.

THE ELECTION

Turks are casting their votes for both a president and a parliament for a five-year term. A candidate must receive more than 50% of the votes to win the presidency in the first round. If no candidate reaches this threshold, a runoff will be held on May 28 between the two leading candidates, who are expected to be Erdogan and opposition leader Kemal Kilicdaroglu.

In 2017, a referendum narrowly passed, which expanded the president's powers and abolished the prime minister's position. As president, Erdogan is responsible for setting policies on Turkey's economic, security, domestic, and international affairs. Voters will also elect 600 members of parliament, selected through party-list proportional representation in 87 regions.

POLLING

Over 64 million Turks are eligible to vote at nearly 192,000 polling stations, including 6 million first-time voters. More than 3.4 million voters overseas completed voting by May 9. Polls opened at 8 a.m. and closed at 5 p.m. on May 14. Voter turnout is typically high in Turkish elections, with almost 87% of eligible voters casting their ballots in 2018. The sale of alcohol is banned on election day.

RESULTS

According to election law, news, forecasts, and commentaries on the vote are prohibited until 6 p.m. Media can only report on election results from 9 p.m. onward, which will be coming in from across Turkey. Election authorities may permit media to report on results earlier. Late on Sunday, there could be a clear indication of the presidential election result.

THE CANDIDATES

PRESIDENT TAYYIP ERDOGAN

Erdogan and his AK Party have been in power for over 20 years, and he aims to extend his term as Turkey's longest-serving ruler. He won the first round in 2018 with 52.6% of the vote, but current polls show his support to be around 44-45%.

KEMAL KILICDAROGLU

Kilicdaroglu is the joint presidential candidate of the six-party main opposition alliance. He is also the chairman of the Republican People's Party (CHP), established by the founder of modern Turkey, Mustafa Kemal Ataturk. Polls show his support to be close to the critical 50% threshold.

SINAN OGAN

Ogan is a former lawmaker with the Nationalist Movement Party (MHP), an ally of Erdogan's AK Party. Polls show him far behind the other candidates.

MUHARREM INCE

Ince recently withdrew from the presidential race, but his name remains on the ballot paper, and people can still vote for him. Photo by Metuboy, Wikimedia commons.