"It would have been unfair that a country [such as Bulgaria] which has gone through all these stages of applying, then negotiating and knows what it's all about, that we block their SAA [Stabilisation and Association Agreement]", he added.

In the Bulgarian version of the SAA, the word "euro" will not be mentioned and will be replaced by the currency's abbreviation EUR, sidestepping the issue of how the European currency should be transcribed in Bulgarian.

The European Central Bank (ECB) wants the euro to be spelled as "euro" (еуро) in Cyrillic instead of "evro" (евро), which is how it is normally transcribed in the EU's third alphabet.

Sofia refuses and said last week it would not sign the Montenegro agreement – which has to be agreed by all member states - if the problem in the Bulgarian translation of the contract was not solved.

The compromise solution postpones the "evro" row – but does not solve it.

Linked to the EU treaty?

From the Bulgarian side, the recognition that "the problem exists" was welcomed and there are hopes that it will be solved by the end of November, the Bulgarian prime minister said.

"A concrete working group of experts needs to be put into place, so that all the academic and scientific arguments are heard. I think we have all the reasons to raise that question, because the specificity of the Cyrillic alphabet as a new EU alphabet has to be taken into account", he said.

Mr Stanishev expressed a belief that there will be an agreement by the end of next month "because we wouldn't like to put obstacles to such an important political event as the European reform treaty and its ratification. That is not our intention".

He said it would be "extreme" for Bulgaria to veto the new EU treaty – which EU leaders are discussing at the end of this week – over the issue.

"Everybody understands that we are constructive, but every constructivism has to be respected by the other side. But I say again, if there is good will, a reasonable solution can be found that does not create cultural absurdities".

So far, the ECB has only put forward the argument that "the name of the common currency unit must be the same in all the official languages of the EU".

But Sofia is pointing out that "the existence of different alphabets" should be taken into account. It also notes that in its EU accession agreement, it is written that the euro would be called "evro" in Bulgaria.