PARIS — He said she was telling lies. She called him arrogant. He accused her of repeating “stupidities”. She cut him off and told him not to lecture her. He shook his head sadly and she laughed sarcastically.

The debate on Wednesday night between France’s two presidential candidates, Ms Marine Le Pen of the far-right National Front and the centrist former economy minister, Mr Emmanuel Macron, was more like an angry American-style television shoutfest than the reasoned discussion of issues the French have become accustomed to.

It was a study in violent verbal combat: The two talked angrily over each other, cut each other off, shook fists and pointed fingers, leaving the moderators bewildered and helpless.

But it was also a stark demonstration of two radically different visions of France that voters will have to choose between on Sunday in the election’s final round. Mr Macron, 39, the former banker and cool technocrat, educated at France’s finest schools and the beneficiary of a meteoric rise, faced off against Ms Le Pen, 48, the scion of one of the country’s most notorious political families, the inheritor of a far-right party who has tried to move it towards the centre.

The two candidates did not hide their disdain for each other, and their total divergence on all the issues — Europe, terrorism, France’s stagnant economy, Russia — explained why.

“The high priestess of fear is sitting in front of me,” Mr Macron said derisively, having cast his opponent as a dangerous extremist with deep ties to her party’s dark past. He made a point of repeating her name, to remind viewers of her parental filiation: Her father, Mr Jean-Marie Le Pen, founded the National Front and is associated with its historical posture of anti-Semitism, Holocaust denial and stigmatisation of immigrants.

“You are the France of submission,” Ms Le Pen said with scorn. Mr Macron was merely a heartless banker, in her view. “We’ve seen the choice you’ve made, the cynical choices, that reveal the coldness of the investment banker you have never ceased being.”

He leads her by 20 points in the polls and is considered likely to win on Sunday. The debate is expected to move some voters, but not enough to make up for Ms Le Pen’s substantial polling deficit. She has seen some slight improvement in recent polls and was clearly hoping to destabilise her younger opponent as she did in the first-round debates, when other candidates were present. With nothing to lose and everything to gain, she went for direct frontal attacks.

But Mr Macron generally kept his cool, laying out his programme point by point through the shouting, while Ms Le Pen, true to the scrappy, guerrilla-style party that she leads, spent much of the two-and-a-half-hour contest attacking him. What policy proposals she offered appeared sketchy.

Mr Macron offered his view of a France open to Europe and free trade; staying in the common currency; reinforcing its ties with European nations; dealing firmly with President Vladimir Putin of Russia; and overhauling France’s stultifying and voluminous labour code in order, he said, to generate more jobs.

“We are in the world,” Mr Macron said. “France is not a closed country.”

Ms Le Pen depicted a France with a “total collapse of our industries”, preyed upon by Islamist extremists, demanding ever more government protection from economic vicissitudes and urgently needing to close its borders. “I’m the candidate of that France that we love, who will protect our frontiers, who will protect us from savage globalisation,” she said at the outset.

Mr Macron was a ruthless capitalist, in Ms Le Pen’s familiar neo-populist depiction, ready to sell French industry down the river to hurt workers and help employers. She repeatedly tied Mr Macron to the failed government of the incumbent Socialist President, Mr Franois Hollande, in which Mr Macron served for two years before quitting to start his own political movement.

“You defend private interests,” she sneered. “And behind that there is social ruin.”

Mr Macron replied evenly: “What’s extraordinary is that your strategy is simply to say a lot of lies and propose nothing to help the country.” He pointed out the weaknesses in her generous spending plans, noting the lack of revenue-raising measures to back them. “France and the French deserve better,” he said. “Don’t say stupid things. You are saying a lot of them.”

Some of the sharpest exchanges came over terrorism, which polls show is a major preoccupation for the French. Ms Le Pen cast herself as tougher on the issue, reeling off a series of anti-terrorism measures — experts have suggested that they are either impractical or ineffective — and saying Mr Macron was a weakling on security. Nonetheless, it is one of her signature issues, always drawing a thunderous response when she invokes it at rallies. “You are for laxism,” Ms Le Pen said. “You are complaisant toward Islamist fundamentalism. We’ve got to eradicate fundamentalist ideologies. You won’t do it, because they support you.”

Bristling, Mr Macron pointed out the impracticality of expelling the thousands of people who are in the government’s so-called S-Files because they are considered to constitute some potential danger to the country’s security.

“The S-Files are just information files,” Mr Macron said. “You can be an S-Filer merely for having crossed paths with a jihadist.

“You’ve got to be much more surgical than Le Pen,” he added. “What you are proposing, as usual, is merely powder,” he said, pointing out that as a member of the European Parliament she voted repeatedly against anti-terrorism measures.

She dismissed these criticisms, as she did the entire European Union project. Under her, she said: “French laws will be superior to laws given out by some commissioner whose name we don’t even know.”

Mr Macron posited a diametrically opposed view, insisting that France’s place was in a stronger Europe that could stand up to Mr Putin’s Russia and President Donald Trump’s United States. Ms Le Pen’s idea is that “we’re going to leave Europe because the others can make it, but we can’t,” he said.

“In the face of this spirit of defeat, I am for the spirit of conquest, because France has always succeeded.”