Sarkozy made his comments during an unscheduled visit to a depot of state train operator SNCF, just over a week after transport strikes caused widespread disruption in France.

The unions have threatened further strikes unless the government backs down over the reform and will meet again on Wednesday to decide what to do. If they do decide on further action it may coincide with a nationwide strike by civil servants on November 20, compounding the disruption.

"The street will not make us give in because we're in a democracy. Street blackmail will not work," Sarkozy told a group of workers, who warned him of new stoppages in the weeks ahead.

"I don't agree with you," said Fabien Monteil, of the Sud-Rail union, one of the most militant railway unions.

"I think the street will speak. We will be in the streets soon. It has always worked like that and each time we have made the prime ministers give in," he told Sarkozy.

There are 1,000 workers at the site and the strike rate was 73 percent on October 18. One member of the CGT union, wearing red overalls, refused to shake his hand.

"You are in your role, defending your social benefits. I'm in my role by saying ... you cannot go on like that. And deep down you know that perfectly well," Sarkozy said.