Turkish President Recep Tayyip Erdogan in Sunday's elections risks seeing his vote critically eroded by an unlikely foe -- a religiously conservative party with roots in the same Islamic political ideology as his own.
Temel Karamollaoglu, the mild-mannered but strong-willed leader of the Saadet (Felicity) Party, is among the opposition candidates standing against Erdogan and hoping to push him to at least a second round.
And with parliamentary polls being held on the same day, Saadet has joined an alliance of opposition parties that wants to rob the ruling Justice and Development Party (AKP) of its majority.
For Erdogan to win the presidential poll, he needs at least 50 percent to guarantee outright victory in the first round.
While Saadet and Karamollaoglu are at best expected to improve on their last result by a couple of percentage points, this alone could be enough to tip the balance in what many pundits predict to be a very tight election.
Saadet emerged from the same political movement as Erdogan's late mentor Necmettin Erbakan who for the first time brought political Islam at the centre of politics in the officially secular country.
The 77-year-old Karamollaoglu, leader of Saadet since 2016, told AFP his party fell out with Erdogan's AKP after it moved away from key principles.
"Mr Erdogan declared those principles in the 2002 elections: justice, democracy, freedom of speech and freedom of thought. But he appears to have put them on the shelf now," he said.
Saadet also backed the "No" side in the April 2017 referendum to oppose a package of constitutional amendments granting Erdogan sweeping executive powers.
"There might be a president's office but there also must be a strong parliament. And the justice system must be far from their influence," he said.
Anthony Skinner, MENA director at risk consultancy Verisk Maplecroft, told AFP that Saadet and Karamollaoglu were playing an important role in the elections in "frustrating" Erdogan.
"Karamollaoglu's candidacy in the presidential race is significant in that he could draw votes away from Erdogan who needs as many ballots as he can get to avoid a potentially tough second round vote," he said.
Saadet represents a movement started by Erbakan that startled the secular establishment in Turkey but inspired AKP's co-founders like Erdogan and former president Abdullah Gul.
Erbakan later founded Saadet while Erdogan and his allies in 2002 launched the AKP.
Karamollaoglu even held talks with Gul -- who since leaving the presidency in 2014 has also fallen out with Erdogan -- on standing for the presidency. But the habitually reticent ex-president decided not to put his head above the parapet.
Saadet currently does not have an MP in parliament and received only 0.7 percent of the vote in the 2015 parliamentary elections. However, some polls predict a stronger performance this time.
"He (Karamollaoglu) offers an alternative to pious constituents who have become disillusioned with Erdogan and the AKP," said Skinner.
Saadet is well below the 10-percent threshold required to send MPs to parliament. But its clout has increased by joining the so-called "National Alliance" of opposition parties challenging Erdogan in the parliamentary elections.
Its allies here include the main opposition Republican People's Party (CHP), a staunchly secular grouping which may seem an unlikely bedfellow for the Islamic-rooted Saadet. But being in the alliance means that Saadet could be able to send MPs to parliament.
Karamollaoglu indicated the party regarded with some disdain the AKP's attempts in the early period of its time in power to integrate with the European Union and form a strategic alliance with the United States.
"We said we need to pursue a foreign policy with spine. But those guys left it behind and we are now waiting at Europe's doorstep," Karamollaoglu said.
Karamollaoglu is upbeat about Sunday's vote, saying the opposition can ride a wave of change that also helped leading Turkish businessman Ali Koc end the two-decade reign of long-standing Fenerbahce chairman Aziz Yildirim on June 3.
"The momentum is coming, we saw it from the Fenerbahce congress," he said.