Earlier in the month, France's leading trade unions called for a general nationwide strike against the reform on May 1.
"It will be the biggest May 1 as regards social issues in 30-40 years," Berger told the LCI broadcaster.
As many as 1.5 million people can take to the streets across France on May 1 to protest against the government pension reform, according to CFDT. At the same time, the French Interior Ministry expects up to 650,000 people to take part in May Day demonstrations. Around 100,000-160,000 people usually participate in rallies in France on that day, French media reported.
Around 12,000 law enforcement officers will be deployed across France, with 5,000 officers in the French capital alone, French Interior Minister Gerald Darmanin said earlier in the day.
On April 14, the French Constitutional Council approved the key article of the pension reform bill, which would gradually raise the age of retirement in France from 62 to 64 years by 2030. The reform sparked a strong backlash, prompting people to take to the streets across the country. As many as 12 nationwide demonstrations against the reform have taken place already, with several protests organized by unions attracting over 1 million supporters across France.