Turkish President Ahmet Necdet Sezer today vetoed a controversial amendment to Turkey's new penal code that would reduce penalties for teaching unauthorised courses on the Koran.
The new penal code, a condition for Turkey starting European Union entry talks in October, went into effect on Wednesday without a number of amendments that required Mr Sezer's approval.
All the amendments will now be resubmitted to parliament, while the new code remains in force in its original form.
Turkey is overwhelmingly Muslim but has a secular system of government that separates religion and politics. Critics had accused the ruling Justice and Development Party (AKP), which has Islamist roots, of trying to undermine Turkish secularism by inserting the amendment on Koran courses into the penal code at the last minute before approving it.
The amendment would reduce the jail penalty for opening or running courses in the Koran without official permission to between three and 12 months from three to six years currently.
Mr Sezer, a staunch secularist, had been widely expected to veto the amendment, which the critics say would sap the state's ability to monitor and control radical Islamist groups.
Prime Minister Tayyip Erdogan is under pressure from his conservative political base to relax curbs on religious symbols and freedoms such as the Islamic headscarf. EU diplomats say the question of the Koran courses is a domestic issue for Turkey.
But they say they will carefully monitor the implementation of the wider penal code, which critics say undermines freedom of expression.