PARIS (Reuters) - Conservative President Nicolas Sarkozy made an impassioned final appeal to voters on Friday, saying that a Socialist victory could send France spiraling the way of Greece, as polls showed him narrowing his challenger's lead two days before the vote.
Final opinion polls put Francois Hollande's advantage at as little as four points. But Sarkozy faced an uphill battle after Hollande turned in a polished performance in their only television debate on Wednesday, and far-right and centrist leaders declined to back the unpopular president.
Centrist candidate Francois Bayrou appeared to drive a nail into Sarkozy's political coffin by declaring on Thursday that he would vote for Hollande. In a withering attack, he accused the conservative leader of pandering to the xenophobic far-right and being obsessed with immigration.
National Front candidate Marine Le Pen, who won 17.9 percent on the April 22 first round, had earlier refused to endorse Sarkozy and said she would cast a blank ballot.
At his final campaign rally in the west coast resort of Les Sables d'Olonne, Sarkozy told flag-waving supporters they could still achieve a sensational turnaround on Sunday. If they do not, he will be the first president to fail to win re-election since Valery Giscard d'Estaing in 1981.
"On Sunday, the outcome will be on a razor's edge," Sarkozy said, lashing out at critics of his drift to the right.
"The people of France have never been so injured, hounded and manipulated as in recent weeks ... The silent majority should not have to put up with insults, intolerance and lack of respect."
Hollande spent his final day of campaigning in the northeast region of Moselle, one of the National Front's strongholds. "I do not want a France that is divided between religions, that does not trust itself," he told crowds.
An opinion poll by Ifop-Fiducial on Friday suggested Sarkozy had cut Hollande's lead to just four percentage points, the narrowest margin to date.
"Every vote is going to count," the president told France 3 television, calling for a massive turnout. "I love my country and I don't want to see it go the same way as Greece. I don't want spending, deficits and rising debt, and risk."
The prospect of a victory for Hollande - who has pledged to raise taxes on big companies and the rich and to temper a German-inspired drive for austerity in Europe - had initially alarmed some investors. He would be the first Socialist head of state since Francois Mitterrand left office in 1995.
Yet French 10-year bond yields slipped below 2.9 percent on Friday - their lowest level since October - suggesting there is no panic about Hollande, who has stressed he would aim to quickly pass laws to balance the budget by 2017 if elected.
Despite his lead, Hollande warned his supporters against complacency on Friday, urging a massive turnout that would give the Socialists momentum to win parliamentary elections in June.
"I want a large victory," he told RTL radio. "The French must give the winner the means to act. Do not leave a hobbled victor who will have problems from the day after the vote."
The French vote could usher in a change of direction in European economic policy towards promoting growth.
The runoff coincides with parliamentary elections in Greece, where voters are set to punish mainstream parties for enforcing EU/IMF-imposed austerity, and comes a week before a major German regional election in which Chancellor Angela Merkel may suffer a mid-term rebuff to her strict austerity policies.
Merkel's government has appeared increasingly relaxed at the prospect of a Hollande victory since he made it plain he would not seek to change the essence of a German-backed budget discipline pact signed by 25 EU leaders last month.
"We will work closely together with France, no matter what happens in the election," German Finance Minister Wolfgang Schaeuble said on Friday.
If elected, Hollande would seek to lay the foundations of a new Franco-German consensus on growth and smooth bilateral relations on his first trip to Berlin, his campaign manager Pierre Moscovici said.
Polls conducted since Wednesday evening's nearly three-hour television debate found Sarkozy narrowing the gap even though surveys of viewers of the debate found most felt Hollande was more convincing than the incumbent.
Two polls by Ipsos and BVA found Hollande's lead had narrowed by one point to five percentage points, giving him 52.5 percent to Sarkozy's 47.5 percent.
The debate was watched by more than a third of the 46 million strong electorate, but only 3 percent said it had changed their voting plans.
Even Alain Minc, a political consultant who is one of Sarkozy's closest advisers, acknowledged the Socialist outperformed his champion in the debate.
"I think we all underestimated this guy," Minc told Reuters. "The Francois Hollande we are seeing today is different from the one we all knew ... Either we were wrong or he has changed."
Friday is the last day of official campaigning before a blackout from midnight. Voting booths open at 8 a.m. (0600 GMT) on Sunday and close at 6 p.m. (1600 GMT), except in big cities where they will stay open until 8 p.m.
Projections of the result based on a partial vote count will be published once the last polling stations close.
Sarkozy has fought an uphill battle for re-election as economic gloom, his failure to keep a 2007 promise to cut unemployment to 5 percent, and a dislike of his brash and showy manner have turned many former supporters against him.
Having lagged the blander Hollande for weeks, he needs to win over around 80 percent of Le Pen's voters and at least half of Bayrou's - a tall order - as well as mobilizing first-round abstainers.
Additional reporting by Daniel Flynn, Vicky Buffery and Leigh Thomas; Editing by Kevin Liffey