The Turkish government, already under pressure to recognise EU member Cyprus, is pushing for a date to begin full membership talks and can ill afford a new row over freedom of speech.
Orhan Pamuk, the internationally acclaimed author of My Name is Red, could face up to three years in prison for comments made in a Swiss interview when he condemned the mass killing of Armenians in the aftermath of the First World War.
Denis MacShane, former Europe minister and Labour MP for Rotherham, said: "It is a sickening blow to all pro-Turks in Britain and Europe ... to hear the news that the Turkish authorities seek to persecute this great European writer."
Calling on the European Commission to lobby Turkey to drop the charges, Mr MacShane added: "I will continue to support and argue for (Turkey's) right to start EU membership talks. But if the authorities persist with this attack on a great European writer then many of us who are strong supporters of Turkey will be forced to change our minds."
A Turkish public prosecutor said Mr Pamuk's comments violated Turkey's penal code. The award-winning writer is charged with "denigrating Turkish identity". Mr Pamuk is prohibited from commenting on the charges but his associate and translator Maureen Freely launched a scathing attack over the charge. "How can Turkey possibly claim to be a European country if it has such laws on the books and prosecutors can bring such cases?" she asked.
The row threatens to overshadow the meeting of EU foreign ministers intended to assess the country's compliance with conditions to open membership talks next month.
In recent years, Turkey has had to enact major political and economical reforms to overcome its reputation as a country that violates human rights and has a weak, uncompetitive economy.
Abdullah Gul, the Turkish Foreign Minister, said talks should begin on schedule as Turkey had met all of the objective criteria.
However, preparations for the talks have already hit a major obstacle over Cyprus. In July, Turkey signed a deal extending a customs union with the EU to include Cyprus and nine other countries that joined the bloc in 2004. Turkey upset many EU governments by insisting its signature on the customs deal did not mean Ankara now recognised the Cypriot government.
Critics have seized on Cyprus to call for a watered-down associate member status for Turkey.
Mr Pamuk caused a storm last year when he told the Swiss newspaper Der Tagesanzeiger that "30,000 Kurds and one million Armenians were killed in these lands and nobody but me dares to talk about it."
Turkey denies a genocide of Armenians between 1915 and 1923, claiming instead that hundred of thousands of Armenians died of famine and disease only.Reuse content