The exiled Islamic cleric at the heart of a damaging feud with embattled Turkish Prime Minister Recep Tayyip Erdogan has accused the government of rolling back on democratic reforms.
Fethullah Gulen also warned in an interview with the Wall Street Journal published Tuesday that possible retrials for hundreds of army officers accused of coup plots could deal a blow to efforts to end the military's tutelage over democratic institutions.
Erdogan has accused Gulen and his Hizmet network of acting as a "state within a state" to try to topple the government through a sweeping corruption probe targeting political and business leaders.
The Islamic-leaning government has retaliated by launching a purge of the police, moving to tighten controls over the judiciary and even trying to mend fences with the army it once fought hard to rein in.
"A broad spectrum of Turkish people, including Hizmet participants, supported AKP (the ruling Justice and Development Party) for democratising reforms, for ending the military tutelage over politics and for moving Turkey forward in the EU accession process," Gulen told the Journal.
But he said Turks were now "upset that in the last two years the democratic progress is now being reversed" and that moves to draft a new civilian constitution had been abandoned.
Gulen has many supporters in the police and judiciary in Turkey as well as a variety of businesses, media outlets and a school network, although he says it does not have direct links with any political party.
His interview was published as Erdogan was in Brussels in a bid to push Turkey's long march to membership of the European Union, facing criticism that government actions were putting democracy under threat.
Gulen, a 73-year-old preacher who has lived in the United States since 1999 to escape charges in Turkey of "anti-secular" activities, also sounded the alarm over suggestions that fresh trials could be held for hundreds of army officers jailed for coup plots against the AKP government.
He said the push for the retrials appeared to be "politically motivated rather than a desire for justice" and would represent a dramatic reversal of efforts to rein in the military, which has waged three coups in Turkey's modern history.