Istanbul (AFP) - Third-party candidate Muharrem Ince on Thursday withdrew from Turkey’s tight presidential election in a shock move that raised the chances of an opposition first-round victory.

The 59-year-old announced his decision after being targeted by an online smear campaign that included doctored images of him meeting women and riding around in fancy cars.

The secular nationalist picked up 30.6 percent of the vote when he challenged President Recep Tayyip Erdogan in 2018 polls.

He then quit the main opposition party and launched his own movement that began to pull votes away from secular leader Kemal Kilicdaroglu – the joint candidate of the anti-Erdogan bloc.

“I’m withdrawing my candidacy,” Ince told reporters ahead of Sunday’s presidential and parliamentary ballot. “I am doing this for my country.”

Ince had come under fierce attack from the opposition for entering the campaign just two months before the vote.

Critics saw him as a spoiler candidate who could only help Erdogan extend his two-decade rule until 2028. He has already been in power since 2003.

Ince argued that he offered voters a more vibrant alternative to the 74-year-old Kilicdaroglu – a bookish former civil servant with a dire national election record against Erdogan.

The announcement appeared to catch Turkey’s 69-year-old leader off guard.

“One of the candidates has withdrawn. It is impossible to understand why this happened. Honestly, I am sad,” Erdogan told a rally in Ankara.

“I wish he had continued until the end.”

- Narrow margins -

The last opinion polls suggested that Kilicdaroglu was leading Erdogan by a few percentage points but falling just short of breaking the 50-percent threshold required for a first-round win.

Erdogan’s campaign has been hampered by Turkey’s worst economic crisis since the 1990s and public frustration at the crackdown he unleashed after surviving a 2016 coup.

The opposition is now also more united than in any past campaign against Erdogan.

Kilicdaroglu’s six-party alliance spans Turkey’s religious and cultural spectrum and includes some of Erdogan’s own former allies.

It is the type of coalition that Erdogan and his Islamic-rooted party excelled at building in order to keep winning at the polls.

This made Ince’s decision to run particularly frustrating for Erdogan’s opponents.

His popularity has been ebbing away after touching nearly 15 percent.

The latest surveys showed him picking up between two and four percent of the vote.

But that might be enough to put Kilicdaroglu over the top.

A snap Metropoll survey released Thursday had 49 percent of Ince’s support falling to Kilicdaroglu and 22 percent going to Erdogan.

Ince notably did not endorse any candidate after dropping out.

His name will also still appear on the presidential ballot.

- Blaming Russia -

A fourth minor candidate – nationalist Sinan Ogan – is believed to be mostly drawing votes away from Erdogan.

“Another crazy day in Turkish politics,” emerging markets economist Timothy Ash remarked.

“Ince withdraws, with the assumption that most of his votes now go to Kilicdaroglu, making it possible/more likely (for a Kilicdaroglu) first round win.”

Kilicdaroglu has been appealing for days for Ince to formally back his candidacy.

“Let’s put aside the old resentments,” Kilicdaroglu tweeted on Thursday.

“We welcome Mr. Ince to the Turkish (opposition) table. Please come, please.”

Kilicdaroglu also alleged that Erdogan’s off-and-on ally Russia was behind the smear campaign.

“Dear Russian friends,” Kilicdaroglu said on Twitter. “You are behind the montages, conspiracies, deep fakes and tapes that were exposed in this country yesterday,” he said without providing details or reasons for his allegations.

“If you want our friendship after May 15, get your hands off the Turkish state. We are still in favour of cooperation and friendship.”

Russian officials issued no immediate response.