Dozens of leading Turkish intellectuals have urged the government to scrap laws limiting freedom of speech that have led to court cases against prominent figures, including Orhan Pamuk, Turkey's best-known novelist.
According to the Anatolia news agency, the declaration, signed by 169 writers, artists, journalists and academics, said that Pamuk's trial was "a grave interference in our country's democratisation process".
Pamuk went on trial earlier this month on charges of "denigrating Turkish national identity" with remarks about the mass killings of Armenians under the Ottoman Empire to a Swiss magazine in February.
He risks between six months and three years in jail.
The declaration on Monday urged the government to scrap the article used against Pamuk and another penal code provision that allows up to 15 years in jail for those who disseminate propaganda via the media against "fundamental national interests" in return for material benefits from foreigners.
Among the signatories were Yasar Kemal, a writer, and Fazil Say, a pianist.
Turkey hopes to join the EU and
talks are under way
A recent increase in court cases against intellectuals has cast a pall on Turkey's commitment to EU democracy norms, only months after it started long-awaited membership talks on 4 October.
The court adjourned the case against Pamuk to 7 February to await a decision by the justice ministry, whose authorisation is needed to proceed with the trial.
Turkish academics have meanwhile increased pressure on the government of Recep Tayyip Erdogan, the prime minister, on another front.
A board overseeing Turkish universities asked the country's top administrative court on Monday to cancel a decree making university access easier for graduates of Islamic schools.
The board backs the academics' argument that the government decree flouts Turkey's secular system.
The Higher Education Board (YOK) asked the court to suspend and then cancel several provisions in the decree, which came into force this month, Isa Esme, its deputy-chairman told Anatolia news agency.
The petition argued that the decree breached "the principle of secularism outlined as one of the Republic's unchangable attributes in the constitution" by putting in place a system encouraging students to attend religious schools.
Prime Minister Erdogan is under
fire for the education decree
Religious high schools in Turkey, which by law are responsible for raising preachers and other Muslim clergy, are regarded by many as a breeding ground for Islamist political movements.
So far, the notoriously complicated university entrance system made it almost impossible for graduates of such schools to gain a place at higher education institutions to study anything but divinity.
For Erdogan, himself a graduate of a religious school, the reform constitutes a promise made to his electorate before the elections in November 2002 that swept his Justice and Development party to power.