Tempers have frayed at a European Union summit designed to reach agreement on a new constitution and commission head.
Jacques Chirac is concerned about the successor to Romano Prodi
The UK and France criticised each other over the slow progress of the deals which are crucial to the EU's future.
France said the UK was making too many demands for special treatment, while London opposes Paris's choice for a new European Commission president.
In a sign of progress at the Brussels summit, Germany and France said they would back a constitutional draft.
Agreement has also been reached on one of the issues that torpedoed constitutional talks last year - resistance by smaller nations to plans for new voting rules.
The new plan says measures must have the backing of at least 55% of EU states, representing at least 65% of the total population, in order to pass.
Irish Prime Minister Bertie Ahern, whose country holds the rotating EU presidency, said progress had also been made on picking someone to lead the European Commission.
But correspondents say a lot was left to be accomplished.
Late-night wrangles over a constitution and who should succeed Romano Prodi as commission president spilled over into the second day.
Catherine Colonna, a spokeswoman for French President Jacques Chirac, said France had been pushed as far as it would go over the constitution.
The UK is believed to have won concessions on its concerns such as preserving national vetoes.
The UK disagrees with Germany's choice for commissioner
Ms Colonna said: "We will not agree to further dilute what has been proposed by the Irish presidency. We have to stop the backsliding."
Her comments followed remarks on Thursday by Mr Chirac himself who said the EU had to "avoid being blocked by a single country" - seen by observers as a veiled attack on Britain for its threat to veto the constitution's text if it cedes power to Brussels in key areas.
A spokesman for UK Prime Minister Tony Blair hit back at that, saying: "It was unfortunate that President Chirac chose to attack our position before the negotiations had begun."
Correspondents note that spats between the UK and France are nothing new.
The UK is also at odds with both France and Germany over a successor to Mr Prodi.
France and Germany have backed Belgian Prime Minister Guy Verhofstadt, but Britain opposes him on the grounds that he could be too eager to make the EU more federal.
Among other candidates, a UK commissioner, Chris Patten, has been proposed - but President Chirac said he did not think it was a good idea to have a candidate from "a country which doesn't take part in all European policies".
Guy Verhofstadt, Belgian PM
Jean-Claude Juncker, Luxembourg PM
Antonio Vitorino, EU Commissioner
Pat Cox, European Parliament President
Bertie Ahern, Irish PM
Chris Patten, EU Commissioner
Mr Blair's spokesman also attacked Germany for trying to link a deal on the constitution with the issue of the presidency, saying: "We are operating in a Europe of 25, not a Europe of six or two or one."
Mr Prodi is stepping down as head of the commission when his five-year term ends in October.