The controversial reforms, which are designed to loosen France’s labour laws and slash the unemployment rate, include a cap on compensation for unfair dismissal and greater freedom to hire and fire employees.
The reforms will also give employers more flexibility to adapt pay and working hours to changing market conditions.
But Philippe Martinez, the head of the far-left CGT union, said that his greatest “fears had been confirmed” after the government presented the five decrees laying out the reforms to unions and employers.
He said: “The labour reform – which is far from revolutionary – marks the end of the traditional employment contract in France.”
He confirmed the union was planning a wave of nationwide protests on September 12 and called on “the young and old” to join him.
Far-left MP Alexis Corbière denounced a “premeditated assault” on the country’s labour code, adding that the “regressive” reforms – which are to be passed before the end of this month – were “a step backwards not forwards”.
Mr Corbière, who urged dissidents to take part in the CGT protests, added that his party, France Unbowed, planned to organise a second wave of protests on September 23.
The Socialist party also denounced the “unbearable” measures in a statement: “The decrees will make it easier for companies to fire workers, who will be robbed of their rights…. They will also create a power imbalance between employers and employees.”
Labour minister Muriel Penicaud described the five decrees as a “transformation of the labour rules on an unprecedented scale”, adding the new labour code would “encourage social dialogue” and help “build trust” between employers and employees.
Her comments echoed those of Edouard Philippe, France’s conservative prime minister, who said the reforms would help drive down unemployment, which remains worryingly high in France.
He said: “The truth is that for bosses and foreign investors, the existing labour code is seen as a brake on hiring and investment.”