The "Berlin Declaration," to be signed by all 27 European Union member states in the German capital on March 25, seeks to define the bloc's successes since the founding 1957 Treaty of Rome and its future ambitions.

But in Brussels even the act of patting each other on the back is fodder for discord and the German EU presidency was keeping details of the declaration document under wraps as EU leaders gathered in Brussels on Thursday for a two-day summit.

"I don't think it is the time or place to present the Berlin Declaration," Merkel told reporters.

But she handed her fellow leaders an outline, Spanish Foreign Minister Miguel Angel Moratinos said, in which she set out the main points she feels should be included, including immigration and climate change.

On foreign relations "a commitment for a more active security policy and a policy of cooperation and development," were put forward, he added.

European Parliament president Hans-Gert Poettering suggested that the Union's roots should be acknowledged, asking whether it would be possible "to find some form of words ... some way of describing our roots, Greek philosophy, Roman law, Judeo-Christian heritage".

"As the president of the European parliament I do not have a mandate to call for a reference to God," he added, "there is a majority in the parliament that does not support that position."

One thing that Merkel is clear on is that the final product should be short -- two or three pages -- and unadorned by the kind of eurobabble, jargon and diplomatic subtleties which make so much of the EU's output incomprehensible to the layperson.

To that end, an as yet unnamed scribe will help fashion the final version, rather than a team of EU bureaucrats, according to the German presidency.

"They are doing it the right way," said a senior British official. "They are not going to let a committee kill this by endless machinations and regurgitations."

So what achievements should the declaration trumpet?

There will be no quibbles over the fact that Europe's major players have avoided going to war with each other since the Treaty of Rome was signed, but identifying other common highlights is problematic.

Some point to the euro and the Schengen era of visa-free travel, but fewer than half of all EU states use the common currency or enjoy all the benefits of free movement within the bloc.

The main sticking point, however, is the section dealing with the EU's future goals, which the German presidency hopes will help focus attention on reviving the EU's constitution, which was rejected by French and Dutch voters in 2005.

Merkel had originally hoped that the "Berlin Declaration" would contain a direct reference to the constitution, but ditched the idea amid staunch opposition from countries like Britain and Poland.

"We won't storm the walls to impose the word 'constitution'," said an official with the German presidency.

Another red flag issue is the idea of championing a 'European social model' as prescribed by Europe's left wing which wants to put a more human face on the bloc's free trade and globalisation tendencies.

"The European social model is something we are going to refer to in the Berlin declaration," said Merkel.

However there remains no overall consensus on what exactly the term means.

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