Despite a flurry of diplomatic activity over the weekend, the British EU presidency has failed to find a suitable response to Turkey's stance, which could harm its long-held membership ambitions.
Tensions mounted in July when, while signing a protocol extending a customs accord with the EU to the bloc's 10 newest states - including Cyprus - Turkey declared this did not amount to a recognition of the Nicosia government.
The EU ministers are seeking agreement on a "counter-declaration", but differences over how strongly it should press Ankara to endorse the divided island have so far prevented an accord.
Few new opportunities are likely before 3 October, when Turkey's membership negotiations are to begin, and Britain concedes it may be forced to call a special meeting of EU foreign ministers, possibly on 26 September.
Erdogan says the EU is placing
new conditions on Ankara
"We remain hopeful that we won't have to drag the ministers to Brussels," a spokesman for the presidency said.
Last week, Britain and France sought support for a compromise stating that Turkey should recognise Cyprus before joining, but that failed to win enough backing in two meetings of EU ambassadors.
Cyprus, which gained independence from Britain in 1960, has been split since 1974 when the Turkish military occupied its northern third in response to a Greek-inspired coup.
The island has never emerged from its division into predominantly Greek-Cypriot and Turkish-Cypriot sectors, although some travel restrictions between them have eased.
As far as Cyprus is concerned, Turkey has stifled its economy by banning Cypriot-flagged vessels, which make up the EU's third largest fleet, from entering its ports.
"To raise certain questions that have no pertinence is not worthy of international diplomatic ethics. It is rude"
Recep Tayyip Erdogan,
Turkish prime minister
In the latest draft of their "counter-declaration", EU ministers would stress that any failure by Turkey to respect customs "obligations in full will affect the overall progress in the [accession] negotiations".
All 25 EU members accept that clause, one EU diplomat says, but some disagree on a passage reading: "Prior recognition of all member states is a necessary component of accession."
The EU diplomat said Cyprus, its key ally Greece and the Czech Republic had refused to accept the wording of the draft, but he gave no further details.
Cyprus maintains that it has strong support for its own draft, which calls for Turkey to recognise it during the membership process and not just before it joins, possibly in 10 to 15 years.
"Support for the Cyprus government's position was encouraging and it obliges the EU presidency to take these views on board and come back with a more positive document," said a Cypriot government spokesman.
While the Union debates what position to take, Ankara has grown increasingly impatient, with Prime Minister Recep Tayyip Erdogan accusing the bloc of placing new conditions on its membership.
"After everything we have done, they are still asking whether accession talks should begin or not," he said.
"To raise certain questions that have no pertinence is not worthy of international diplomatic ethics. It is rude."