Turkish President Recep Tayyip Erdogan on June 6 claimed one of his main rivals was trying to “steal” votes among Turkey’s Kurdish community by visiting a pro-Kurdish candidate in jail on terrorism charges.

Erdogan threw the accusation at Muharrem Ince, the candidate of the secular Republican People’s Party (CHP), while addressing supporters in the northwestern Sakarya province. After being nominated to contest the June 24 presidential race on May 7, Ince called on Erdogan to release Selahattin Demirtas, the jailed candidate of the pro-Kurdish People’s Democratic Party (HDP), saying: “The HDP are also children of this nation, [and your party] AKP are also children of this country... Don’t keep Demirtas in jail. Come, let’s race like men.” Kurdish votes could prove decisive in whether or not Islamic-rooted AKP secures a majority in the simultaneous parliamentary vote. On May 29, a row blew up over a plan to relocate polling stations in some areas with a high Kurdish population vote, with the HDP saying it was a scheme to repress votes in AKP’s favour.

Erdogan describes Demirtas as a terrorist responsible for the deaths of Kurdish civilians during unrest three years ago. Demirtas denies the charges and human rights groups have claimed they were trumped up in a bid to crush dissent amid Turkey’s state of emergency, introduced nearly 23 months ago following a failed coup.

Erdogan, expected to win re-election to a newly empowered executive presidency, might face a difficult cohabitation in power with the parliament if his AKP cannot win a majority.

“Those visiting him aren’t doing this for freedom, they think they can steal votes from there. You won’t be able to. My people will teach a lesson on June 24 to the person who visits such a terrorist,” he told the election rally.

Demirtas, who has won votes beyond his Kurdish core constituency in recent elections, faces 142 years in jail on terrorism charges as well as four years for insulting Erdogan in a different case.

Ince, 54, a combative parliamentarian and former physics teacher, has accused Erdogan of driving Turkey “to the cliff” through ideological politics and a determination to control the monetary policy of the central bank.

Former interior minister Meral Aksener, who leads the fledgling Iyi (Good) Party, is the other leading opposition candidate. If either Ince or Aksener pushes Erdogan to a run-off vote, their supporters are expected to unite in an attempt at defeating the incumbent.

On May 2, four opposition parties including CHP and Iyi, agreed to unite in a broad formal alliance to fight Erdogan and the AKP. The move surprised analysts as Turkey’s opposition has been fragmented for years.