ANKARA, Turkey - Prime Minister Recep Tayyip Erdogan’s rare expression of sympathy for Turkish generals last month may signal a split with Turkey’s most powerful religious movement, undermining the unity of his government.

Erdogan, who has backed a series of inquiries into alleged coup plots that have left hundreds of army officers in prison, was critical of the latest inquiry, saying it was “unsettling’’ the country. Previously, he blocked an attempt by one of the investigations to interrogate Turkey’s intelligence chief.

Many Turkish analysts saw those actions as a warning directed at Fethullah Gulen, a Turkish imam based in the United States and leader of a movement widely seen here as a driving force behind the prosecutions.

Curbing the army’s power has been a key policy for Erdogan, who has presided over record growth after ending an era of fragile coalition governments. Now, he and Gulen may no longer share the same goals, threatening the stability critical to Erdogan’s economic success.

“All movements start to crack once they’ve reached a certain point,’’ said Atila Yesilada, an analyst at Global Source Partners, a political and economic research firm. “If Gulen believes that Erdogan will never share political power with him, he will organize within alternative institutions.’’

Gulen has been in Pennsylvania since he left Turkey in March 1999 to undergo a health checkup in the United States, according to Ahmet Sik’s book “The Imam’s Army.’’ In June that year, Turkish TV showed footage of the imam telling followers to spread his ideas and conquer the state from within in the name of Islam, the book says.

His followers are known as the Cemaat, or Congregation, in Turkey. He described the movement as “faith-based, pacifist, pluralist, colorful, and pro-democratic.’’ Detractors say it has cells in key areas of the Turkish state.