Bulgaria puts price on Turkey's EU membership

"Turkey is surely able to pay this sum, after all, it's the 16th largest economic power in the world," he said, putting a total of $20 billion (€14 billion) on the settlement. "One of the three conditions of Turkey's full membership of the EU is solving the problem of the real estate of Thracian refugees."

The Ottoman Empire in 1913 expelled hundreds of thousands of ethnic Bulgarians from lands lying on the western side of the Bosphorus. It became the Republic of Turkey in 1923 and recognised the rights of the displaced people in a 1925 treaty, but the agreement was never implemented, Bulgaria says.

An official in the Bulgarian government press office, Veselin Ninov, told EUobserver on Monday that Mr Dimitrov's statement reflects government policy and that the dispute is being handled by a Bulgarian-Turkish intergovernmental working group.

Mr Ninov mentioned a different sum, however.

"This is a matter of official government policy. There is a contract between the two parties, dated 1925. This is an official contract, so, according to the contracting parties, the Turkish government has to repay $10 billion to $12 billion (€8 billion) to the Bulgarian refugees," he said.

Mr Ninov described the issue as being "more historical than political."

But when asked if Bulgaria is ready to veto progress in EU-Turkey negotiations because of the dispute, he said: "There is such an option. But this is just one of many other conditions of Bulgarian support for Turkish membership. There are also issues relating to energy and water management projects."

Bulgarian prime minister Boyko Borisov is set to raise the compensation question during a visit to Turkey in January or February, Mr Ninov added.

Turkey began EU accession talks in 2005 and has so far opened 12 out of 35 negotiating chapters.

Its military occupation of northern Cyprus, an EU member, has so far proved the main stumbling block to progress. But the EU commission is also concerned about Turkey's respect for human rights, while Germany and France are opposed to Turkish EU entry on broader political grounds.

The issue of historically displaced people has become increasingly disruptive since the EU's 2004 wave of enlargement.

In a recent example, Czech president Vaclav Klaus last year tried to block ratification of the Lisbon Treaty unless the EU inserted a special clause ruling out compensation for Germans expelled from Czechoslovakia after World War II.

The Turkish foreign ministry and the EU commission were unavailable for an immediate comment.