French President warned Wednesday that his far-right rival risked sparking a "civil war" if she was elected and implemented her plans to ban the Muslim headscarf in public.
During a televised presidential , Le Pen confirmed that she stood by her controversial idea of banning the headscarf, which she called "a uniform imposed by Islamists", but she said she was not "fighting against Islam."
Macron, 44, responded: "You are going to cause a civil war. I say this sincerely."
France faces a stark choice in Sunday's second-round run-off between the centrist Macron and the anti-immigration Le Pen, who will seek to become the country's first far-right head of state in an outcome that would send shockwaves around Europe.
There was little cordiality in the bruising three-hour live televised debate, with Macron repeatedly seeking to land punches on Le Pen over her record, while she sought to keep the focus on the government's performance.
She also vowed to put an end to "anarchic and massive" immigration into France, claiming it was worsening crime which she said was becoming "unbearable" for people all over the country.
In his five years as president, Macron has been accused of enacting Islamophobic policies in the name of French secularism, in part using an approved last year.
France banned Muslim women and girls from wearing the headscarf at schools in 2004.
It banned the wearing of the niqab or burqa in public in 2011.
With Russia's invasion of Ukraine overshadowing the campaign, Macron angrily zeroed in on a loan Le Pen's party had taken from a Czech-Russian bank ahead of her 2017 election campaign.
"You are dependent on the Russian government and you are dependent on Mr (Russian President Vladimir) Putin," Macron said. "When you speak to Russia you are speaking to your banker."
Macron also referred to Le Pen's past recognition of Russia's 2014 annexation of the Ukrainian peninsula of Crimea. "Why did you do this?" he asked.
Le Pen replied that she was "an absolutely and totally free woman", arguing that her party had only taken that loan as it could not find financing in France where banks refused to lend to her.
Macron adopted a variety of poses to express scepticism at her arguments, raising his eyebrows, leaning his chin on his fists and lamenting in apparent bewilderment "Madame Le Pen... Madame Le Pen!"