By Sarah Rainsford
BBC News, Istanbul
A Turkish court has ruled that a controversial conference on the mass killing of Armenians living under the Ottoman Empire should be suspended.
Armenians still remember over one million who died in 1915
The conference of academics and intellectuals was to offer a critical look at the official approach to the events of 1915.
Armenians want the killings classified as genocide, but Turkey refuses, pointing to casualties on both sides.
It is the second time the conference has been called off.
The cancellation comes just 10 days before Turkey is due to begin accession talks for membership of the European Union.
This was no ordinary academic conference. The delegates were set to discuss the fate of the Ottoman Armenians 90 years ago, one of the most sensitive subjects in Turkey.
The first attempt to stage the debate, in May, was abandoned after Turkey's Justice Minister accused organisers of stabbing Turkey in the back.
This time a group of nationalist lawyers petitioned a court at the last minute and once again the conference is off.
The alleged massacre of more than one million Armenians in 1915 has long been a taboo subject in Turkey.
It was illegal even to discuss the issue until a very recent reform inspired by Turkey's bid for membership of the European Union.
Just 10 days before EU accession talks are due to begin, this court ruling is likely to embarrass the authorities.
The prime minister, though, has already voiced his concern, calling the decision undemocratic.
Recep Tayyip Erdogan said that although you may not approve of a point of view, that does not mean you should prevent others from expressing it.
The university does have the right of appeal, but lawyers here say there is now little to no chance the ground-breaking debate can go ahead as planned on Friday.