The French will have to work two years longer to age 64 before retiring, if the reform, announced on Tuesday, is adopted by parliament.
They will also need to work longer to get a full pension.
"I don't understand the principle of making people work longer when there are lots of young people looking for work."
Unions will in any case get the support of the left-wing Nupes coalition in parliament, which urged workers to protest on Jan. 19.
Under its plan, the retirement age will be raised by three months per year from September, reaching the target age of 64 in 2030.