The European Parliament has backed plans to start talks on Turkish accession, but insisted on a number of provisos before it is allowed entry.
Turkey rejects bids to allow les than full entry to the EU bloc
MPs insisted Ankara recognise the killings of thousands of Armenians in 1915 as genocide. Turkey denies that the killings were systematic.
MPs also postponed a vote on ratifying Turkey's customs arrangements because of its refusal to recognise Cyprus.
Neither decision affects entry talks which are due to start on 3 October.
The negotiations, once started, are expected to take about 10 years.
The European Commission said the postponement of the vote was an "own goal" by the parliament.
The Armenian killings have long been a taboo subject in Turkey. Armenians, supported by 15 countries, including France, Switzerland, Russia and Argentina, accuses the then Ottoman rulers of carrying out a "genocide".
Turkey disputes the charge, saying that a few hundred thousand died and that the deaths occurred in a civil war in which many Turks were also killed.
But Turkey's Prime Minister Tayyip Erdogan did condemn a Turkish court's decision to order the cancellation of a conference about the killings which was due to have been held last week.
Further talks about Turkey's accession are set for Thursday to try to resolve a deadlock over the question of the negotiating framework for Turkish membership.
Turkey has been clear that it will not accept the option of privileged partnership, which Austria is pushing to be inserted into the negotiating framework; only full membership will do.
The BBC's Jonny Dymond says that even if they get the framework they want, the membership process will be a long and painful one.
This is partly because so much needs to be done by Turkey to adapt itself to EU rules. It needs to absorb the 80,000 page long EU rule book into its domestic law.
One member state has already boasted about the number of potential vetoes it has during the negotiations process. There is also the question of Turkey's continuing human rights reform process.
The European Commission has promised to monitor closely how Turkey proceeds. If it is deemed to be slipping backwards in theory or practice, then the commission will not hesitate to make its misgivings public.
To add to all the difficulties, there is the question of public expectations in Turkey.
Our correspondent says many Turks see the membership process as a genuine negotiation, a process of give and take. But by and large, Turkey has simply to do what it is told if it wants to join the club - which for many is a sharp change in culture, he adds.