Ministers from 17 European Union countries, including Bulgaria, are due to meet in the Spanish capital, Madrid, to raise their voices in support of the idea of an EU constitution.
The countries sending ministers to the meeting are: Austria, Belgium, Bulgaria, Cyprus, Estonia, Finland, Greece, Hungary, Italy, Latvia, Lithuania, Luxembourg, Malta, Romania, Slovakia, Slovenia and Spain.
The 17 countries approved the constitution, unlike France and Netherlands, whose voters rejected the draft last year.
Germany, which is currently presiding the EU and has made it its top priority to revive the constitution, dismissed the meeting as unhelpful. The country will be represented only by an observer.
Observers from Ireland and Portugal, which have not yet ratified the constitution, are also expected to attend.
In a joint article published in a number of European newspapers, Spain's Alberto Navarro and Luxembourg's Nicolas Schmit, who organize the conference, say that in today's globalised world "a united and capable Europe is more necessary than ever".
"We cannot resign ourselves to Europe being no more than a huge market or a free trade area," they write.
"We want a political Europe that can speak with one voice, and with one minister of foreign affairs and a common foreign service."