By Patrick Bartlett BBC Europe business correspondent

EU leaders will struggle to contain the crisis

After a week of bruising exchanges over Iraq, Europe's efforts to build a common foreign policy have never seemed in greater disarray.

The bleak mood will not be eased by the knowledge that as they start their discussions over dinner on Thursday evening, bombs may already be falling on Baghdad.

Perhaps we shall find a little more humility among the large member states Chris Patten EU external affairs commissioner

The British Prime Minister, Tony Blair, and French President Jacques Chirac arrived in Brussels still seething over the diplomatic war of words triggered by France's opposition to a second UN resolution.

The French Foreign Ministry said on Wednesday it was "shocked and upset" at the "unworthy" criticism of French policy by British ministers.

"No-one on the British side will seek to belittle or dismiss the difficulties that exist, " said one UK diplomat. "It will not be business as usual."

Biggest crisis

The crisis which has divided the EU's heavyweights - pitching Britain and Spain against France and Germany - is a severe setback to efforts to enhance Europe's international clout.

Blair and Chirac: Not business as usual

The EU's 15 leaders will doubtless try publicly to rally round common principles, such as the basic goal of disarming Iraq.

But they will struggle to contain what is being described by some here as the biggest foreign policy crisis the EU has experienced.

"Perhaps we shall find a little more humility among the large member states, " said Chris Patten, the EU's external affairs commissioner.

"They can surely see ... how much they have reduced their common influence as a result of squabbling. "

Resistance

But that may prove optimistic. Even talks on Europe's role in the post-war reconstruction of Iraq look fraught with difficulty.

Some member states are resisting being drawn into the aftermath of a war they do not support, especially when there is as yet no UN mandate for such a project.

The diplomatic rift has also effectively sabotaged the work of the European Convention, the body drawing up a future EU constitution.

A planned progress report, due to be discussed at the summit, has been postponed amid fears that to present it now would invite open ridicule.

Overshadowed

The leaders will be more united when it comes to encouraging President Bush to pursue his road map for peace in the Middle East, with the aim of creating a Palestinian state by 2005.

But even here, some countries are sceptical about America's sincerity given the initiative's timing, just as the US goes to war.

The disunity over Iraq has also completely overshadowed the original purpose of the summit - to boost job creation and re-invigorate the EU's economic reform programme.