ANKARA (AP)–A prosecutor on Tuesday filed charges against a political science professor for allegedly insulting the legacy of the founder of modern Turkey. Atilla Yayla’s university has already suspended him amid allegations that he criticized Mustafa Kemal Ataturk, whose portrait hangs in government offices and whose ideas are still the republic’s most sacred principles, 68 years after his death. Prosecutor Ahmet Guven on Tuesday filed charges against Yayla for "insulting the legacy of Ataturk." Yayla could receive up to three years in prison if tried and convicted. No trial date was set yet. Turkey, which is aspiring to join the European Union, has been roundly condemned for not doing enough to curb extreme nationalist sentimen’s and to protect freedom of expression. Yayla said in his Nov. 18 speech that the era of one-party rule under Ataturk, from 1925 to 1945, was not as progressive as the official ideology would have Turks believe but was "regressive in some respects." He also criticized the statues and pictures of Ataturk, saying Europeans would be baffled to see the portraits of just one man on the walls. Ankara’s Gazi University was inundated with fax messages accusing Yayla of treason and demanding that he be fired. Yayla has insisted that he was not insulting Ataturk but questioning his legacy, as well as the rigid way some followers interpret his principles to oppose liberal reforms and impose strict secular laws such as the ban on headscarves at universities. "As an academic, I must be free to think, to search and share findings," Yayla, 50, has said in an interview at the Ankara-based Association for Liberal Thinking, an organization he co-founded in 1994. "If Turkey wants to be a civilized country, academics must be able to scientifically criticize and evaluate Ataturk’s ideas."