By Chris Morris BBC Europe correspondent in Le Touquet

Tony Blair and Jacques Chirac may have wanted to talk about progress on defence policy, immigration and education - but the spotlight at this summit was shining on the subject of Iraq, and under its unforgiving glare they could only agree to disagree.

Tension has risen because the stakes are so high

They both want to disarm Saddam Hussein, and they want to do it through the United Nations.

But there was no sign that Mr Blair had any success in persuading Mr Chirac to accept a second UN resolution which would authorise the use of military force against Iraq.

Pressed on the point, the two leaders replied with the briefest of answers, and often refused to comment. Mr Chirac was standing his ground.

The French president said war "was the worst of all solutions", and he was determined that the UN weapons inspectors should be given more time. Past inspections, he pointed out, have destroyed more Iraqi weapons than the Gulf War in 1991.

Test

France still has not ruled out using its veto at the UN, even though that would trigger a lasting crisis in its relations with Washington.

France wants to slow the march toward war on Iraq

Some observers still believe Mr Chirac will be talked into reluctant co-operation at the 11th hour - others argue that he may hold out, emboldened by public opposition to war.

For Tony Blair, this was an opportunity to make his case to Mr Chirac, not a time for great public declarations.

He said everyone should listen carefully to the evidence which the US Secretary of State Colin Powell intends to present to the UN Security Council, and wait for the next report of chief weapons inspector Hans Blix on 14 February.

Both Mr Blair and Mr Chirac also went out of their way to emphasise the strength and importance of the "entente cordiale" between Britain and France.

But the past couple of weeks have been a real test for cross-Channel relations, and a bruising experience for anyone trying to promote a common European Union policy towards Iraq.

Endgame

President Chirac was not even consulted about the letter signed last week by eight European leaders, including Mr Blair, which called for unity with the United States - and he was not at all pleased.

French officials said he made several "ironic" comments about the letter during the course of his meeting with Mr Blair.

It is perhaps par for the course. Tension has risen because the stakes are so high.

For months there has been plenty of diplomatic bluff and brinkmanship on Iraq, but the endgame is rapidly approaching.

Both leaders know they will soon have to make critical decisions, which could have lasting effects on their political careers. But they did not have to make them today.