Turkey is due to open a new chapter in its negotiations to join the EU, but a long-running dispute over Cyprus means other chapters are blocked.
Candidate countries have to open and then close 35 chapters of talks bringing their own laws and institutions in line with the EU's.
The opening of Turkey's 13th chapter - on food and veterinary safety - may turn out to be the last.
Cyprus joined the EU in 2004, but Turkey backs its breakaway north.
The northern part of the island is still governed by an unrecognised administration.
The Greek-Cypriot government vetoed a plan to allow the Turkish part to trade with EU member states. Turkey retaliated by blocking access to its ports for Cypriot ships, which led the EU to freeze eight negotiating chapters.
Together with France, Germany and Austria, Cyprus is blocking all but three of the remaining chapters and Turkish officials say they expect even those three will also be blocked.
That means Turkey's troubled candidacy cannot move forward unless there is a settlement of the Cyprus conflict and that prospect still looks remote.
Croatia started its EU negotiations at the same time as Turkey. It expects to close all 35 chapters by the end of this year and become a full member in 2012.
Turkish officials insist EU membership is still their primary foreign policy goal, but they complain that they face far more obstacles than other countries.
Opinion polls here suggest the Turkish public is increasingly pessimistic about their country's chances of being accepted by the EU.