Britain and France clashed over credit ratings on Friday, adding to tensions that erupted over Prime Minister David Cameron's veto of a treaty on euro zone fiscal integration.
Deputy Prime Minister Nick Clegg told French Prime Minister Francois Fillon French criticism of the British economy was unacceptable and called for a cooling of the rhetoric.
World Bank President Robert Zoellick said he was deeply troubled by exchanges between Britain and France over resolving the euro zone debt crisis.
Differences over the debt crisis affecting both the euro zone and Britain have chilled an initially warm relationship between the eurosceptic Cameron and French President Nicolas Sarkozy.
Relations between the neighbours and age-old rivals grew more tense when Cameron refused to sign up a week ago to a European summit deal on the euro zone's debt crisis calling for a tougher deficit and debt regime.
The decision left Britain isolated among the 27 EU members.
Earlier on Friday Finance Minister Francois Baroin had joined a chorus of French criticism of the British economy.
The economic situation in Britain today is very worrying, and you'd rather be French than British in economic terms, Baroin told Europe 1 radio.
Fillon raised similar concerns about Britain and the rating agencies on Thursday, saying during a visit to Brazil: When I look at our British friends, who are even more indebted than us and carrying a bigger deficit, what I see is that the ratings agencies so far don't seem to have noticed.
Some French leaders are irked that powerful global credit ratings agencies seem to take a rosier view of the British economy than the French.
Britain, which has embarked on tough austerity policies to curb a big budget deficit, retains a top-notch credit rating.
Credit rating agency Fitch reaffirmed France's triple-A rating on Friday but said the outlook was negative, meaning it could be downgraded within two years. It said it thought a comprehensive solution to the euro zone's debt crisis was beyond reach.
Clegg's office said Fillon called him from Rio de Janeiro to clarify his comments.
Fillon made clear it had not been his intention to call into question the UK's rating but to highlight that ratings agencies appeared more focused on economic governance than deficit levels, the statement said.
Clegg accepted his explanation but said recent remarks by members of the French government about the British economy were simply unacceptable and that steps should be taken to calm the rhetoric. Prime Minister Fillon agreed, it said.
Bank of France chief Christian Noyer also attacked ratings agencies this week, saying that if they considered economic fundamentals they should downgrade Britain - which had as much debt, more inflation, less growth than us - before France.
In an interview with Saturday's Guardian newspaper, Clegg said Britain might have been caught in the crossfire of the campaign for next year's French presidential election, when Sarkozy is expected to seek re-election.
There is nothing more popular in French politics ... than giving 'perfidious Albion' a good kicking from time to time. At the end of the day, France and Britain have always worked out it is better to work together rather than shout at each other across the Channel, Clegg said.
I just think we all need to go away, have a bit of hiatus, a bit of time to have Christmas, to eat some mince pies or whatever the French equivalent is. Everyone is a bit tired, he said.
Clegg, leader of the pro-European Liberal Democrats, Britain's junior coalition partner, has said he was bitterly disappointed by the outcome of the EU summit.
Fillon's office told Reuters the prime minister had called Clegg to defuse the tension. Fillon in no way wanted to call into question Britain's rating, his office said.
The World Bank's Zoellick said on Friday the euro zone's financial and economic problems were far from solved.
I have been deeply troubled over the past couple of days to see some of the commentary going across the English Channel, not only comments from France but also from Brussels, Zoellick told an audience at the Atlantic Council in Washington.
The criticism has not been just one way. Some British ministers have also disparaged France's economic performance.
Writing in the London Evening Standard newspaper last month, British Finance Minister George Osborne said: The markets are even asking questions about France. That's why the French have now had two emergency budgets in four months to try to get ahead of the curve, as we did last year.
(Additional reporting by Nicholas Vinocur and Brian Love in Paris, Fiona Shaikh in London; Lesley Wroughton in Washington; Editing by Tim Pearce)