Opponents of Turkish entry fear that Brussels could not integrate such a vast Muslim state, writes Denis Staunton.
After more than 40 years knocking on Europe's door, Turkey expects this week to get a green light from EU leaders for the start of talks which could lead to full membership of the EU within a decade. As Thursday's summit in Brussels approaches, however, the debate over Turkey's European ambitions has become more heated, with the Turkish prime minister, Mr Tayyip Erdogan, accusing the EU of discriminating against his country.
"I get the impression Turkey is being held to stricter criteria than other candidates. No other country had to wait 41 years at the door of the European Union. We have done all that was demanded of us, and the Europeans are still hesitating. That can clearly be called discrimination," he told Germany's Bild am Sonntag newspaper yesterday.
The EU leaders are almost certain to agree this week to start negotiations with Turkey, but they remain divided over the conditions to be set for such talks.
Turkey's champions are led by Britain and Germany but include Ireland, Italy, Spain, Belgium, the Czech Republic and the European Commission. They want to start negotiations in the first half of 2005 and to apply the same conditions to Turkey as applied to the 10 states which joined the EU last May. The most important of these conditions are the so-called "Copenhagen criteria" for democracy, minority rights and the rule of law.
A more sceptical group, led by France and Austria but including Denmark, Slovakia and Hungary, wants to start negotiations at the end of 2005 and to define the talks as "open-ended". This would open up the prospect of granting Turkey a "privileged partnership" with the EU rather than full membership.
EU diplomats believe that the phrase "privileged partnership" is unlikely to appear in this week's summit conclusions, but Austria's chancellor, Mr Wolfgang Schuessel, is seeking to persuade other conservative leaders to support a reference to "other options" apart from full EU membership.
This week's decision is further complicated by Turkey's relationship with Cyprus, where more than 30,000 Turkish soldiers are stationed on the northern part of the island. Turkey does not recognise the government of the southern Greek part of the island, which joined the EU in May.
Ankara has made clear that it will not make any gesture towards recognising the Greek Cypriot state before this week's summit, although an expanded customs union with the EU could imply a de facto recognition on Turkey's part. The Greek Cypriots want full diplomatic recognition from Ankara but have played down suggestions that they might veto the decision to start membership talks with Turkey.
Meanwhile, Mr Erdogan has been hinting that Turkey could walk away from negotiations with the EU if too many conditions are attached to the talks. Yesterday, he outlined three major expectations for Turkey from the Brussels summit.
"Firstly, the Turkish government will only consider full membership. We would never accept a 'privileged partnership'.
"Secondly, we cannot accept any new political demands apart from the 'Copenhagen criteria'.
"Thirdly, the negotiations must begin without delay. That means in the first half of 2005."
This week's decision is emotionally-charged, with Turkey's supporters arguing that a failure to start membership talks would signal to Muslims inside and outside Europe that the EU is a "Judeo-Christian club". They suggest that Turkey, with its moderate Islamist government, could be an important bridge between Europe and the Middle East and point to Turkey's strategic importance - a factor which helps to explain Washington's support for Turkey's EU membership ambitions.
Those who oppose accepting Turkey into the EU fear that Brussels could not integrate such a vast Muslim country with a fast-growing population of 80 million. They point to persistent reports of torture and repression of minorities in Turkey and express concern about the prospect of the EU sharing borders with Iran, Iraq and Syria.
Sceptics warn that admitting Turkey would make it difficult for the EU to exclude such countries as Belarus and Ukraine and could open up the possibility of North African countries such as Morocco joining the EU.
Such fears feed into the incendiary debate in some EU countries over the integration of Muslims in western Europe, a debate which has been sharpened by the recent murder of Theo Van Gogh, a Dutch film-maker who was critical of Islam.
If Turkey does eventually join the EU, it is likely to face permanent restrictions on the free movement of labour, to prevent mass migration to richer European countries. Current member-states are also likely to ensure that Turkey will not benefit from the generous structural funds and agricultural subsidies which countries such as Ireland have enjoyed.
Even if EU leaders agree this week to start membership talks next year, Turkey will face further political hurdles throughout the accession process.
France has indicated that it could put any further enlargement of the EU to a referendum, a step which other sceptical countries could follow.
Germany's opposition conservatives are hoping to make Turkey an election issue in 2006 and Bavaria's prime minister, Mr Edmund Stoiber, yesterday told the Frankfurter Allgemeine Sonntagszeitung that they would reverse Germany's policy on the issue if elected. "In any case, a federal government led by us in 2006 would, together with partners such as France, do everything to prevent Turkey becoming a full member of the EU," he said.