French election: Sarkozy and Hollande in final push
Nicolas Sarkozy and Francois Hollande are making their final pitch for votes in one of the most dramatic elections in recent French history.
Opinion polls suggest the incumbent president has cut Mr Hollande's lead slightly but is still trailing his Socialist challenger by some 6%.
Analysts say he needs a major reversal in fortunes to win on Sunday.
He suffered a blow when centrist Francois Bayrou, who took 9.1% in the first round, backed Mr Hollande.
Boosted by the endorsement, Mr Hollande said he wanted a strong mandate.
"If the French people must make a choice, they should do so clearly, overwhelmingly, so the winner has the capacity and means to act," he told RTL radio.
Mr Sarkozy sought to play down the Bayrou news, pointing out that he had won the last presidential election without the centrist's backing.
Appealing for maximum turnout, he told a rally in the west coast resort of Les Sables d'Olonne: "On Sunday, you can't imagine how much everything will hang on a knife edge."
Campaigning officially finishes at midnight local time (22:00 GMT) after which the media in France are meant to refrain from any reporting which might prejudice the ballot until the close of polls on Sunday evening.
'Beaten long ago'
Mr Bayrou, who came fifth in the first round of voting, said he would be voting for Mr Hollande.
Though he once served with the president in a right-wing cabinet, he said Mr Sarkozy had gone too far to the right, abandoning European values and moving too close to the far right's position on immigration.
Speaking to Europe 1 radio on Friday, Mr Sarkozy rejected speculation about the result.
"There is a feeling among the French that this avalanche of commentaries and polls... is robbing them of some of their freedom," he said.
Later, speaking in Les Sables, he said that if he won on Sunday, the world would "look at the French people and say 'hats off... you are a great people because you are a free people'."
A "Follow Friday" message appeared on his official Twitter account urging people to "FF every French man and woman met during the campaign".
Social media analysts say Mr Sarkozy's campaign has been more effective on Facebook, while Mr Hollande's Twitter presence is seen as stronger.
The BBC's Hugh Schofield in Paris reports that unless the polls turn out to be wrong, Mr Sarkozy looks set to be the first French president since Valery Giscard d'Estaing in 1981 not to win a second term.
Both the president and Mr Hollande have reached out to voters who backed far-right National Front (FN) leader Marine Le Pen.
She has already said she will be leaving her ballot blank rather than vote for Mr Sarkozy or his rival.
Ms Le Pen, who attracted 6.4 million votes in the first round, said on Thursday that the election was over as Mr Sarkozy was "beaten a long time ago".
Mr Sarkozy and Mr Hollande engaged in a heated televised debate on Wednesday night, watched by an estimated 17.9 million people.
Guillaume Journeaux, a grocer in the northern French city of Lille who strongly supports Mr Sarkozy, told the BBC News website he was concerned that defeat for his candidate would boost the far right in June's parliamentary elections.
"I am very concerned because a fair few of the people I know on the right say they will join the FN if Hollande wins," he said
"You can barely imagine the knock-out blow we will suffer from the FN if Nicolas Sarkozy loses. We need Nicolas Sarkozy for national cohesion and unity."
The FN currently has no seats in the French National Assembly, which is dominated by Mr Sarkozy's conservative UMP party.
On Friday, Mr Hollande travelled to the eastern city of Forbach to address a rally in a market square.
"You have welcomed me as a candidate - make it on Sunday that I come back as head of state!" he was quoted by tweeters as telling the crowd.
Speaking earlier to RTL, he repeated his determination to renegotiate the EU fiscal compact to include action for growth.
"The country's problems will not disappear with the eventual departure of Nicolas Sarkozy," he said.
"He won't take the public debt, unemployment and social problems with him."
On Thursday, Mr Hollande attended a mass rally in Toulouse with Lionel Jospin, the former Socialist prime minister who was famously eliminated from the first round of the 2002 presidential election by the FN.
Mr Sarkozy held a mass rally of his own in the southern port of Toulon.
The night before, the two rivals had engaged in a heated televised debate, watched by an estimated 17.9 million people.