EU leaders split over president

European leaders are set to gather in an effort to overcome political differences and unite behind a single candidate for the European Union's first president.

The leaders, meeting in Brussels for a working dinner from 1700 GMT on Thursday (0400 AEDT on Friday), will also seek to name a foreign policy supremo, as part of a duo to represent the new-look EU on the world stage from next year.

But the task is far from simple, given the different visions among the 27 nations about what the role the new president should play over what could be a five year term.

On the eve of the talks, Swedish Prime Minister Fredrik Reinfeldt, whose country holds the EU's rotating presidency until the end of the year, appealed to the leaders to keep the horse-trading to a minimum.

"I need of course the collaboration of my colleagues to try to get this through," he said, adding that the summit "might take a few hours, it might take all night."

According to the dinner plan, the meeting is supposed to run three hours.

Experts agree the president should be a technocrat who can build consensus among countries and the EU's main institutions - the council of nations for the 27 member states, the European Commission and the European parliament.

Belgian Prime Minister Herman Van Rompuy remains the favourite but no candidate has emerged who strikes the delicate balance required for either of the key posts, created by the new Lisbon reform treaty.

In recent months a score of names has been raised, and many discarded, as EU leaders sought a personality with charisma yet modest enough not to hog the limelight.

Ahead of the dinner, French President Nicolas Sarkozy and German Chancellor Angela Merkel, who have pledged to push for a common candidate, have planned a press conference for 1630 GMT on Thursday (0330 AEDT on Friday).

"I'm optimistic that we will have an agreement (Thursday) evening," Merkel said on Wednesday.

Former British premier Tony Blair has been the most high-profile name floated, but his key role in the 2003 invasion of Iraq divided Europe and despite continued backing from London, his star has faded.

Typically, a number of candidates have emerged from mid-sized pro-European nations, such as Van Rompuy and Dutch Prime Minister Jan Peter Balkenende.

Luxembourg Prime Minister Jean-Claude Juncker, Europe's longest-serving leader, is also in the running, as is former Irish premier John Bruton.

Calls have mounted for women to be nominated, but only former Latvian president Vaira Vike-Freiberga has come forward, and analysts say she may be too pro-American and anti-Russian.

While it is not set in stone, it is widely accepted that the president should come from the centre-right, which dominates the European parliament, and the foreign affairs chief be a socialist, the second formation.

For the latter, Britain's Foreign Secretary David Miliband was widely touted but he insists he is not available.

Former Italian premier Massimo D'Alema appears to have the right credentials, and Spain is pushing Foreign Minister Miguel Angel Moratinos, while Britain's EU Trade Commissioner Catherine Ashton is another possibility.

After months of speculation, Swedish officials hope for real movement once the leaders are alone at dinner, away from the interest groups driving debate. If consensus proves elusive, the decisions could be made by qualified majority.