Interior Minister Nicolas Sarkozy attacked France's social model and offered veiled criticism for the government's handling of a growing crisis over a jobs law for youths — expected to culminate Tuesday in nationwide strikes and protests.

Police promised increased surveillance on the country's regional and commuter rail network ahead of the protests Tuesday over the new youth employment law, which is expected to cause widespread disruption of train, plane and subway traffic.

The labor law would let companies dismiss workers under 26 without cause during their first two years on the job — a provision the government hopes will make employers more willing to hire younger workers.

"I have come here tonight to tell you that it is necessary, urgent and above all possible to change our habits and conventions," Sarkozy told a crowd Monday in the northern town of Douai.

"We have reached a moment of truth: The French must choose between paralysis and movement."

Sarkozy — who heads the party in power, the Union for a Popular Movement — has made no secret of his wish to become president.

His party will not officially select its candidate until January. President Jacques Chirac is thought to want Prime Minister Dominique de Villepin to succeed him, but Villepin is now embroiled in the jobs law crisis.

Arguing for "a more just France," Sarkozy said a "spirit of compromise where each agrees to take a step toward the other" was needed. He called for a single jobs contract to replace the numerous types of employment contracts currently in effect.

He also said there should be no proposed legislation on social issues without full discussion beforehand, veiled criticism of the way Villepin has forced the jobs law through parliament without debate and has refused to withdraw it despite the protests.

In a renewed effort to break the standoff, Villepin on Monday made a new offer to meet with students and unions Wednesday, a day after the planned protests. The unions, who want the measure withdrawn before any talks, refused.

About 200 demonstrations are planned across the country Tuesday, with the largest winding through Paris. The march will be the sixth in about two weeks in the capital, where some protests have blown up into clashes between youths and police.

The State Department alerted Americans to security concerns surrounding the demonstrations. The announcement, not as strong as a travel warning, said the protests have taken place in areas frequented by tourists.

"Police have responded by using tear gas," the announcement said.

The department said U.S. citizens traveling to or living in France should avoid areas where crowds are expected to gather and to exercise caution, particularly at night.