PARIS — Teachers, mail carriers, bus drivers and other French workers tried to shut down France today in a showdown with President Nicolas Sarkozy over his government's attempt to raise the retirement age by two years to save money.

The battle over the contested retirement reform has gone on for months, but this week could prove decisive. With the Senate expected to pass the pension reform bill by the end of the week, some unions have upped the ante by declaring open-ended strikes, meaning the walkout that begin Tuesday could last for days or even weeks. Past walkouts lasted only one day.

Train drivers launched an open-ended strike Monday night, and the work stoppages widened to other sectors on today. High school students also were joining the fray, with walkouts expected at hundreds of schools.

More than 200 street protests were planned throughout the country. Last month, similar demonstrations brought 1 million people onto the streets, according to police estimates, though union organizers insisted turnout was three times as high.