The hardline leftist, who sees himself as the main voice of opposition to the government’s reform agenda, has likened the labour code reform to a ‘social coup d’état’.
Mr Mélenchon, the head of the Communist-backed France Unbowed political party, provoked a storm of controversy on Saturday after he compared president Emmanuel Macron’s government to the Nazi regime in a hard-edged speech.
The left-winger, who drew tens of thousands to a rally against the labour code reform in Paris, issued a thinly veiled warning to Mr Macron: “We’ve been told that democracy is not the street… It is the street that defeated the kings and that defeated the Nazis.”
The crowd of protesters reacted by chanting “Resistance! Resistance!”
Mr Mélenchon added: “The battle is not over, it is only just starting.”
The far-left firebrand was referring to the president’s interview with American news channel CNN last week, during which Mr Macron said “democracy is not the street,” and vowed to press ahead with his reform agenda in spite of protests.
The controversial comments, however, landed the leftist in trouble and drew sharp responses from Mr Macron’s camp over the weekend.
Government spokesman Christophe Castaner slammed Mr Mélenchon’s “political faux pas” during a radio interview with France Inter, saying it was “morally wrong” of him to put the centrist government on par with the Nazi regime.
Labour minister Muriel Penicaud, the driving force behind the labour code reform Mr Mélenchon is so staunchly opposed to, told Europe 1 radio that she had been “shocked” by the far-left leader’s “shameful and unworthy” comments.
The head of the centrist Republic on the Move parliamentary group, Richard Ferrand, condemned Mr Mélenchon’s speech via Twitter, saying comparing Mr Macron to Adolf Hitler was “absurd”.
Jean-Claude Mailly, the secretary general of the leftist trade union Force Ouvrière, also joined the chorus of criticism, calling the Nazi remarks “shocking”.
Mr Mailly said: “The street did not help bring down the Nazi regime, it was the allies, the Americans, the Russians, etc (who helped crush it).
“If you know a little history, you know that the street helped – in part – bring the Nazis to power, so you must choose your words carefully.”
Mr Mélenchon denied drawing parallels between Mr Macron’s government and the Nazi regime in a blog post, condemning “politics of division” and saying that the controversy had served as a smokescreen to draw attention away from the number of people who had joined Saturday’s demonstration.
According to Mr Mélenchon, 150,000 people took to the streets of Paris on Saturday to protest against the loosening of France’s complex labour laws, while the Paris police department claim that just 30,000 protesters joined the demonstration.