German Chancellor Gerhard Schroeder intends to call for a "pause for reflection" at an EU summit on June 16-17, as he leads the scramble to resolve the deep political crisis over the EU constitution.

German government sources said on Friday that Schroeder believed the leaders of the European Union need to take stock after voters in France and the Netherlands rejected the first text of its kind, shattering efforts to create a framework for the ever-expanding EU bloc.

With polls in Denmark suggesting it, too, will reject the treaty, Britain appearing ready to put its promised referendum on ice and Luxembourg's prime minister forced to put his job on the line, Schroeder has emerged -- almost by default -- as a mediator.

"I will not give up in working for this constitution, for a united Europe which we need," he said on Thursday, after crisis talks in Luxembourg with the EU's current presidency.

On Friday, after talks with Romanian Prime Minister Calin Tariceanu, whose nation wants to join the bloc in 2007, Schroeder said it was "totally untrue" to suggest that EU enlargement should stop.

Concerns that the EU is growing too big too quickly have been cited by voters who have rejected the constitution.

Schroeder got strong support from German President Horst Koehler, who insisted the "European project is not dead".

"The world probably needs it more than ever," Koehler said. "If Europe can learn from its current crisis, it can emerge stronger."

With French President Jacques Chirac compromised by the decisive "no" from his electorate in last Sunday's French referendum, Schroeder -- the other half of the Franco-German engine at the heart of Europe -- has been forced to lead the salvage operation.

He followed his flying visit to Luxembourg by dashing back to Berlin for a brief meeting with Irish Prime Minister Bertie Ahern.

Chirac was due in Berlin on Saturday for a working dinner with Schroeder and the two will meet again in Paris on June 10.

Meanwhile Schroeder will squeeze in another meeting with Luxembourg Prime Minister Jean-Claude Juncker next week.

Then British Prime Minister Tony Blair visits on June 13, just ahead of the summit of EU leaders in Brussels where Schroeder will make his appeal for a period of reflection.

In France, where the "no" vote sparked a government reshuffle, new Foreign Minister Philippe Douste-Blazy insisted his country would remain "at the heart of European integration."

"We are obviously in a difficult situation after two negative referendums," said Douste-Blazy.

While Germany has ratified the constitution, albeit without a referendum, Schroeder and the other defenders of the constitution appeared to be facing an increasingly difficult task to hold the treaty together.

Government sources in London said Britain will announce on Monday that it will put its referendum, planned for next year, on hold.

With Luxembourg the next country to hold a popular vote on the constitution on July 10, Juncker declared he would resign if voters rejected it.

Juncker was speaking after opinion polls showed a surge of support for the "no" camp in Luxembourg, the tiny state which has been a staunch supporter of the European project.

"It is a question of basic decency towards the voters of Luxembourg," he told reporters. "If there is a 'no,' it is not the people who have to quit. It is up to me to go."

In addition, Juncker confirmed that the EU charter, which aims to prevent decision-making gridlock in the expanding bloc, would be definitively dead if more than five EU countries give it the thumbs down.

In Denmark, opinion polls give the "no" camp a clear lead for the first time, less than four months ahead of a September 27 referendum.

But Schroeder insisted the ratification process be allowed to continue, arguing that all 25 EU member states had been promised a right to vote on it.

In Brussels, a spokeswoman for EU foreign policy chief Javier Solana admitted the crisis might make it "a little bit more complicated" for Balkan nations hoping to join the bloc.

Meanwhile the Estonian parliament postponed its ratification of the treaty until the autumn for legal reasons, officials said, but denied the delay was influenced by the French and Dutch results.