However, there is broad acknowledgment among officials, politicians, and analysts in Brussels that coupled with a likely swing to the right in Germany, France could deliver a possibly lethal blow to the ambitions of those countries seeking to upgrade themselves from neighbors to EU member states.
Michael Emerson, a senior analyst at the Center for European Studies in Brussels, says countries such as Ukraine and Georgia will have to abandon their membership hopes for the foreseeable future: "This means that the leaders of Ukraine and Georgia are making great speeches about their ambitions to join the European Union, they are going to find the setting rather an uncomfortable one to carry on making those speeches. That leads absolutely to the question of whether the motivating influence of Europeanization of these states is going to be damaged."
Worryingly for membership hopefuls, enthusiasm for further enlargement is fast losing ground in the one EU institution that has traditionally led the drive -- the European Parliament.
Marianne Mikko is an Estonian deputy who chairs the European Parliament's delegation for Moldova. She told RFE/RL that although there has been a perceptible shift of mood in the parliament against enlargement.
"When we look at Ukraine and Moldova, then with the exception of one European Parliament resolution, there has been talk or promises of membership," she said. "On the other hand, the Action Plans remain in force and integration [with the EU] will continue. I would not overdramatize the situation. I can say, however, that over the past month when it comes specifically to Moldova, I've noticed that in the corridors of the parliament the talk is clearly about the action plans and not whether Moldova could perhaps join the EU in 10-15 years' time."
This, Mikko says, reflects a shared desire on both the left and right of the political spectrum to avoid any damage to the "yes" campaign in France.
One source told RFE/RL the loss of enthusiasm is so palpable that Moldovan President Vladimir Voronin could be denied the opportunity to address the parliament's Foreign Affairs Committee when he visits its seat in Strasbourg early next month. An appearance before the plenary session is apparently completely out of the question.
Emerson traces the recent developments in France and Germany to broader factors that suggest the shift in the public mood against enlargement will not be a short-term phenomenon.
"The broad tendencies behind all of that are two quite different things. One, it's the anti-Muslim sentiment and the Christian identity club on the one hand. The second is all those who want to keep a relatively compact and controlled European Union, a governable European Union."
Emerson says the first casualty of a French "no" and a likely right-of-center victory in Germany's September elections will be Turkey. Ankara has been given the green light to begin accession talks in October. Emerson says the talks may yet begin, but with a "cloud hanging over them." He adds that the Turkish membership application has "no chances of succeeding" until the end of the "political cycle," likely to be introduced by a French "no" vote in this weekend's referendum, a victory for the Germany's Christian Democrats (CDU), and a possible victory for the right-of-center French politician Nicolas Sarkozy in the country's presidential elections in 2007.
Emerson says the western Balkan states could also be vulnerable and see their accession hopes thwarted for the foreseeable future. He says Bulgaria and Romania have a "chance of just getting through before the door is shut."
The European Commission today was forced to admit that although both states have already signed their accession treaties, their entry could still be blocked if the treaties are not ratified. CDU officials in Germany suggested this week neither country is ready to join the EU in 2007 as planned.
Germany also leads a group of EU countries attempting to roll back proposed budget increases for the bloc for the years 2007 to 2013. The commission has said that, as a result, funding for its external relations activities could decrease by nearly 20 percent.
However, Emerson says things could yet turn out better for those countries that have no EU membership aspirations -- such as those in Central Asia or the Arab world. He says the rollback of enlargement ambitions of some countries means the EU can tackle the others with greater clarity.
"I think possibly [the EU foreign policy] would become more proactive. They will be forced take the neighborhood policy all the more seriously because it becomes the only game. If the enlargement game is not there then it is the neighborhood game and the question is how to play it."
Emerson says that enlargement has so far been treated in the EU as internal policy, whereas relations with countries in the European neighborhood have been classified as external policy. Emerson says that what he describes as a "fuzzy overlap" between the two until now is likely to disappear in the coming years. This means, he says that once the EU is no longer inhibited by fears of provoking further membership requests, it might run "quite a robust foreign policy."