The protesters oppose sweeping changes to France's labor code, which make it easier to lay off workers. But Macron defends his reforms, saying they're needed to bring down France's stubbornly high unemployment rate.
Several thousand demonstrators answered a call from far-left opposition party leader Jean-Luc Melenchon on Saturday to march in Paris against President Emmanuel Macron's labor reforms.
The crowd shouted "resistance, resistance" and no to "a social coup d'etat."
The changes to France's complicated labor codes increase flexibility for small businesses to negotiate pay and other working conditions with their employees. Previously these details were bound by national agreements.
Macron's 36 reform measures across five separate decrees aim to ensure greater flexibility in negotiating working conditions, allow businesses with fewer than 20 employees to negotiate directly with staff and bypass union agreements, enable employers to hire and fire with greater ease and limit redundancy payouts for unfair dismissals.
The president said the reforms would increase entrepreneurship which, in turn, would help reduce France's stubbornly high unemployment rate of 9.6 percent.
Melenchon's France Unbowed party has accused Macron of destroying decades of hard-fought social gains.
In a strong speech, Melenchon referred to France's revolutionary history and the street demonstrations of the past: "It was on the streets that kings, Nazis, the Juppe plan were beaten," he said.