More than 300,000 people took to the Greek capital's streets in protest against the US-British attack on Iraq over the previous weeks. A new massive turnout is expected on Wednesday, when the country's umbrella trade union calls on its members to rally "for the enlargement and against the war".

The government has already said it will take "unprecedented" measures to protect the two-day gathering, in which UN Secretary General Kofi Annan and Russian Foreign Minister Igor Ivanov will also be present.

"We won't gamble. Around 10,000 policemen will be on the streets during those two days," said Greek deputy minister for public order Evangelos Malesios.

Greece's Minister for European Affairs Tassos Yiannitsis voiced the wish the Greek people "would not create problems".

"I am sure the Greek people are mature and can differentiate between what happens on Wednesday (EU enlargement) and whatever else happened previously (Iraq war)," Greek government spokesman Telemachos Chytiris said on Friday.

But Christos Polyzogopoulos, president of Greece's umbrella trade union GSEE and member of the country's ruling socialist party, has called British Prime Minister Tony Blair, Spanish Prime Minister Jose Maria Aznar and Italian Prime Minister Silvio Berlusconi, who are all firm backers of the war, "enemies of Europe".

If not forbidden by police, the rally is to follow the well-beaten two-kilometre (1.2 mile) path from Athens' main square past the embassies of Italy, Britain, Spain and the United States. Once more, the US and British missions will be protected by armoured vans and riot police squads in full gear.

Just a few hundred metres from where demonstrators will gather on Wednesday morning, EU leaders will hear a report on the Union's future constitution by former French president Valery Giscard d'Estaing, who presides over a 105-member convention working on a relevant draft.

The Greek EU presidency admitted the Iraq war will have an effect on the debate over Europe's future. The EU's 15 members were openly split over the question if they should support the US-British attack against Baghdad. Spain and Italy offered Washington and London political backing. Germany and France led the anti-war front.

"It's exactly because it has problems... that we want a strong Europe," Yiannitsis said in a radio interview.

The UN's role in post-war Iraq will dominate Annan's talks in Athens. "Mr. Annan will make use of the presence of all the (EU) leaders to discuss with them the UN's role and how it can cooperate with the EU," Yiannitsis said.

In view of meeting the assembled EU leadership in Athens, Annan cancelled a previously planned European tour.

The Greeks want to turn the signature ceremony, taking place at the foot of the renowned classical monument of the Acropolis, into a symbol of European unity, which was dealt a heavy blow during the Iraq war.

Since January the Greek EU presidency spent most of its energies on the sisyphean task of hammering out a common European position on Iraq instead of focusing on the Union's further political and economic integration as initially planned.

But beyond its symbolical value, the Greeks said the meeting will also be of substance. "We're in a crucial juncture in the process of enlargement," a diplomatic source said.

On Thursday morning, prime ministers and top government officials from 40 countries, including the enlarged EU and its eastern neighbours, gather in a so-called European Conference.

SPACE.WIRE