PARIS - French President Nicolas Sarkozy on Sunday fiercely denied that he was offered campaign funding from late Libyan leader Moammar Gadhafi, as new challenges piled up against him a week ahead of the country's presidential runoff.

Sarkozy also rebuffed leftist critics who compared his campaign rhetoric with that of France's Nazi collaborators, reviving ugly wartime memories in what has been a particularly bitter presidential race.

Polls predict Sarkozy will lose the May 6 runoff to Socialist Francois Hollande, who promises government-funded jobs programs and higher taxes on the rich - pledges that resonate with a recession-weary electorate.

Both men staged rousing rallies Sunday on opposite ends of the country, with Hollande sounding victorious already and Sarkozy calling for Europe to protect its civilization.

The campaign funding allegation originates from a year-old claim by Gadhafi's son Seif al-Islam Gadhafi that Libya financed Sarkozy's 2007 presidential bid. The allegation came as Sarkozy was campaigning for international air strikes against Gadhafi's forces to stop his crackdown on Libyan rebels.

Although no evidence has emerged that the funding ever took place, French website Mediapart reported Saturday that it had obtained a 2006 Libyan document signed by Gadhafi's then-intelligence chief Moussa Koussa with an offer by the regime to spend about $66 million on Sarkozy's campaign.

"It's a setup, it's a slanderous remark," Sarkozy said on Canal Plus television Sunday, accusing Mediapart of being a mouthpiece of the left.

Hollande's campaign team urged judicial authorities to investigate, as did Segolene Royal, the runner-up in 2007.

Supporters of the Socialist leader gathered Sunday for a rally in Paris where Hollande said his presidency would be a "refusal of austerity."

He wants to renegotiate a hard-fought European treaty on budget tightening, saying economies need more government stimulus. Critics say his plans will dig France deeper into unsustainable debt.

"We have to change the orientation of Europe. Things are starting to move," Hollande said.

Earlier in the day, Hollande honored Jews deported during World War II, visiting a memorial and museum to the Holocaust in Paris and praising the museum's work as crucial "for Jews and for humanity."

About 76,000 Jews, plus thousands of gypsies and others, were deported from Nazi-occupied France to concentration camps during World War II, and the overwhelming majority never returned. Since the 1950s, the last Sunday of April has been a day when France honors those deported.

Sarkozy paid tribute to French Jews during a rally in the southern city of Toulouse, where a gunman killed three Jewish schoolchildren and a rabbi last month.