President Erdogan faces the biggest threat to his 20-year rule

Millions of Turks head to the polls on Sunday in what is expected to be Turkey’s most important election in two decades, the results of which will have implications far beyond its own borders.

The country of 85 million people holds both its presidential and legislative elections on May 14. For the presidency – which should be tight – if no candidate wins more than 50%, the vote goes to a second round two weeks later.

Incumbent President Recep Tayyip Erdogan faces his toughest test after two decades in office, grappling with public anger over deteriorating economic conditions and the government’s slow response to a series of earthquakes devastating attacks in February that killed more than 50,000 people.

His main opponent, Kemal Kilicdaroglu, 74, of the centre-left Republican People’s Party (CHP), is running as a unity candidate representing six different parties who all want to see Erdogan out of power.

In a potentially game-changing development, one of the four presidential candidates, Muharrem Ince, withdrew from the race on Thursday. A former member of the CHP, he had come under heavy criticism for splitting the opposition vote in a way that would hurt Kilicdaroglu’s chances.

Now, with Ince out of the race, his votes could go to Erdogan’s top challenger, Kilicdaroglu, helping him immensely and causing more problems for the 69-year-old Erdogan.

Another crucial factor will be turnout: more than 5 million young Turks will be voting for the first time, and the higher the youth turnout, the better it is for the challenger candidate and the worse for the incumbent, according to election analysts.

With such a high-stakes contest, many inside and outside the country are wondering if Erdogan can challenge the result if he doesn’t win.

“The most likely tactic he will use to try and sway the vote will be to use his influence in the election commission (the YSK), the courts and the media to build a narrative that the election should be renewed or that they are illegitimate,” said Ryan Bohl, principal analyst for the Middle East and North Africa at Rane. Erdogan did so in 2019 when his party narrowly lost the race for mayor of Istanbul, only to lose again by a larger margin after demanding a new race.

Some even fear violence and instability if the result is disputed, which would bring more volatility to Turkey’s already damaged economy. Turkish and foreign rights analysts and activists have for years been sounding the alarm increasingly autocratic governance coming from Erdogan’s administration.

CNBC has contacted the office of the Turkish Presidency for comment.

The outcome of the election and its impact on stability in the country, which sits as a crossroads between Europe and Asia and is home to NATO’s second largest army, is of paramount importance both in both nationally and internationally.

“There is so much at stake for President Erdogan and his AKP (Justice and Development Party) for the first time, as his 20-year rule over Turkey may come to an end as the unified opposition has succeeded in maintain a strong alliance and stay on a positive campaign that brings hope,” said Hakan Akbas, managing director of Istanbul-Washington-based consultancy Strategic Advisory Services.

This is similar, he noted, to “what Istanbul Mayor Emrak Imamoglu did to win twice against Erdogan’s AKP candidate in the 2019 municipal elections.”

Imamoglu, a popular figure who was expected to run for president as a formidable opponent of Erdogan, was sentenced in December to almost three years in prison and banned from politics for what a court described as an insult to the judges of the Supreme Electoral Council (YSK). Imamoglu and his supporters say the charges are purely political and were influenced by Erdogan and his party to sabotage his political ambitions.

Politically, Turkey is deeply divided, with candidates using polarizing and alarmist messaging to try to galvanize voters. But for most Turkish citizens, the economy is a priority as the country faces a cost of living crisis with the official inflation figure hovering around 50% and a currency that has lost 77% of its value compared to dollar in five years.