Four days from an election that may make French history by sending an incumbent home after one term for the first time in 31 years, president Nicolas Sarkozy and his challenger Francois Hollande pulled no punches in the only debate of the campaign.

The two faced off Wednesday night in a confrontation that was notable more for its acrimony and name-calling than the substantial arguments it offered voters, many of whom remain undecided.

Capturing those undecideds - including a record 18 percent of voters who chose the right-wing Front National in the first round - is key to victory in Sunday's runoff, when Hollande may become the first Socialist president of France since Francois Mitterrand left office in 1995.    
 
Fighting hard for his political life after losing the first round of voting, Sarkozy defended strongly his record as a centre-right president who steered the country through not one but several crises. But he failed to land a decisive blow on an opponent who is ahead by seven points in the polls. That wasn't for lack of trying:  known for his belligerent debating style, Sarkozy was even more confrontational than usual, calling his opponent a "liar engaging in petty libel." He flatly told Hollande "I am not your pupil!" while the two were trying to one-up each other on the subject of who knew European Union rules better. "You think you can say anything to me," Hollande replied at one point, aghast. 

Yet, the two-hour debate, with the contenders directly facing each other and with two moderators to one side, had begun on serious policy matters. Europe, and how to get out of a Europe-wide financial crisis, was one of the dominant themes, with Hollande proposing less fiscal austerity and more growth-oriented policies and Sarkozy casting himself as the man who knew better how to steer through complex European policy. 

"My duty if I should become president is to give Europe a different orientation than the one you gave it," said Hollande, attacking Sarkozy's austerity policies: "I see that many heads of government such as Spain's and Italy's agree. I sense the line is moving. There is a new spirit (...) I want to bring back growth."

That was early on in the the debate, and things rapidly devolved into a fight from there, as  Sarkozy shot back "You think the French watching us tonight want to end up like the Spaniards?" and told his opponent that he "knows Europe badly. You can't pound the table there, you make compromises." A piqued Hollande interrupted him saying "I know Europe well," and with that, the gloves were off.    

Hollande kept a generally more measured tone than Sarkozy, but did not shy away from attacking. When the president lamented that opponents had compared him to past Fascist dictators, Hollande quipped "You'll have a hard time trying to pass for a victim" and said that he had been insulted himself. "Do you want a list of your friends, your very friends, who compared me to who knows what bestiary? I've been called every animal in the zoo!" said the Socialist leader, who has never held elective office and has drawn unfavorable comparisons for his laid-back style.
   
Yet Hollande tacked rightward as well, by assuring that he would not tolerate segregated schedules for men and women in public pools or halal meat (from animals slaughtered according to Muslim ritual) in school canteens, a message clearly meant for the right-wing voters whose main concern is the fear of an Islamized Europe.

But pandering to the National Front, which is seen as outside the mainstream by many French voters, is a risky tactic, and Hollande balanced any opening to the right with language meant to appeal to the left: "The privileged have been too sheltered. Therefore fiscal justice, social justice, territorial justice will inspire me," he said.  

But the debate didn't remain long on the lofty terrain of ideas. A mention of Dominique Strauss-Kahn, the man who would likely have been in Hollande's place as Socialist standard-bearer if allegations of sexual misconduct had not brought him down, reignited the insults. "I have no lessons to learn from a party that was enthusiastically behind Dominique Strauss-Kahn!" yelled Sarkozy. His rival replied that he knew nothing of DSK's questionable private life. "Pontius Pilate!" came the venomous reply from the president. Still, biblical insults aside, the French may have learned more about the men vying for the highest office of the Republic - or at least they have according to Hollande himself: "That was," he said in conclusion, "a useful debate."