Turkish President Recep Tayyip Erdoğan has filed a criminal complaint against Muharrem İnce, the main opposition candidate in June 24 presidential elections, for comments connecting the president to Fethullah Gülen, the U.S.-based preacher accused of ordering the failed 2016 military coup, the secular Cumhuriyet newspaper reported.

The Gülen movement was once a strong ally of Erdoğan’s ruling Justice and Development Party (AKP), which came to power in 2002. But after years in which the AKP ran government and Gülen followers used senior positions in the judiciary to target their secular mutual rivals, the Islamist factions fell into rivalry that culminated in late 2013 when Gülenist judges targeted a number of ministers and their relatives with corruption charges.

Erdoğan’s criminal complaint follows a statement by İnce on Monday, in which he accused the president of having visited Gülen in 2001 in order to receive the preacher’s blessing before founding the AKP.

Erdoğan is demanding $100,000 in damages from İnce, citing an attack on his personal rights and claiming the Republican People’s Party (CHP) candidate is serving the interests of a terrorist organisation, namely the Gülen movement.

Erdoğan admits to having met Gülen while serving as the mayor of Istanbul in the 1990s, but denies having visited him in the United States where the preacher moved in 1999.