Brussels, Belgium ? Delegates are struggling to finish a European Union constitution that will determine whether the bloc remains a loose alliance of sovereign countries or moves toward a super-state that may someday rival the United States.

A 105-member convention has been working for 15 months to create a document to manage the EU more efficiently after the bloc swells from its current 15 members to 25 members comprising 450 million citizens next year.

The convention chairman, former French President Valery Giscard d’Estaing, admitted that delegates will need more time because conflicting national interests and widely differing visions for Europe have complicated their efforts.

Giscard d’Estaing hoped to finish a complete draft in time for a June 19 EU summit in Greece, but said Wednesday only the first two parts of the draft will be ready by then. Framers will meet in July to finish the final part, which includes the contentious issue of how many votes each country will hold.

The challenge has been to balance the powers of individual governments with those of the EU, which many Europeans consider a faceless, bloated bureaucracy not accountable to voters.

The deliberations have underscored the historical contradictions between those anxious to protect national sovereignty and those who believe the future of Europe lies in something similar to a federal state.

Small countries such as Austria, Denmark and Belgium also fear their influence will be submerged by big nations such as Germany and France.

The negative sentiments are most pronounced in Britain. Many British newspapers warn the constitution will spell the end of country’s sovereignty.

“The biggest betrayal in our history,” proclaimed the Sun newspaper of London after part of the draft was released last month.

Conrad Black, owner of the Telegraph newspapers, warned that framers wanted to establish a “ramshackle structure of alternative influence” to the United States.

Mindful of public sensitivities, British Prime Minister Tony Blair persuaded Giscard d’Estaing to drop his plan to rename the EU “United Europe.”

Blair also has lobbied against references to federalism a red flag for British EU critics.