Top French ministers warned Monday against picking a fight with Germany after their Socialist Party accused Chancellor Angela Merkel of being "selfish" in her drive for eurozone austerity.

With Franco-German relations already at their lowest level in years, senior government officials sought to head off further tensions with Berlin over the leaked draft of a Socialist Party document on Europe.

Foreign Minister Laurent Fabius said that while President Francois Hollande's government welcomed debate on European economic policy, it must not descend into open conflict.

"Debate yes, pugilism no. It is not normal to call into question such or such a leader," Fabius said on Europe 1 radio. "There is no reason to face off one country against another."

In the draft leaked on Friday, Hollande's Socialist Party slammed Merkel for her insistance on austerity as a solution to Europe's debt crisis.

It accused conservative Merkel, who faces elections on September 22, of being obsessed with "Berlin's trade balance and her electoral future".

Senior Socialists have also recently called for a "confrontation" with Berlin to push France's efforts to focus on economic growth measures over austerity.

Finance Minister Pierre Moscovici said attacks on Germany would do no good.

"This idea that there must be a 'confrontation' with Germany is wrong and completely counter-productive," Moscovici told Le Monde newspaper.

"We cannot hope to move things forward through denunciation, stigmatisation or division," he said, adding that such attitudes were "a certain way to doom us from the start".

Prime Minister Jean-Marc Ayrault also insisted on "Franco-German friendship", telling newspaper La Depeche du Midi that "like all friendships, it does not exclude debate on ideas."

German government spokesman Steffen Seibert on Monday said the relationship between Germany and France was "essential" and what mattered for Berlin were the actions of the French government.

But some in the German press said the leaked text reflected sour grapes on the part of the French for losing influence in Europe.

"The Socialists were promising to show Europe the way. A year after they moved into (France's presidential residence) the Elysee, this sounds like a joke," Berliner Zeitung wrote.

Socialist officials insisted the leaked document was in no way final and did not represent the party's official view.

"This draft was not meant to make its way into the media," the party's European affairs secretary, Jean-Christophe Cambadelis, told LCI television.

"If we find out who gave this text to the press, I will ask that they be suspended from the Socialist Party," he said.

The leak follows months of sniping from the Socialists' left flank, who have accused Hollande of not being forceful enough in his dealings with Merkel.

Hollande is suffering from record-low ratings in the polls about a year after coming to power, with some in his party saying the president has not done enough to push Socialist priorities.

Franco-German ties have noticeably cooled since Hollande took over last year from right-winger Nicolas Sarkozy, who enjoyed especially close ties with Merkel.

Top officials in Sarkozy's UMP party on Monday accused Hollande of being "personally responsible" for "the continuing and appalling degradation in Franco-German relations."

In a joint statement, UMP party chief Jean-Francois Cope and ex-prime minister Francois Fillon denounced the "anti-German climate gaining ground in the Socialist Party" and accused Hollande of seeking to isolate Merkel within Europe.