PARIS - Hundreds of thousands of French teachers and other public sector workers went on strike on Thursday to protest against job cuts and reforms announced by conservative President Nicolas Sarkozy's government.

It was the third broad public sector strike since Sarkozy took office a year ago promising reforms to reinvigorate the economy. Unions are already planning a bigger strike on May 22 involving a larger chunk of the workforce.

©REUTERS/Charles Platiau

French high school students demonstrate with teachers and other public sector workers in Paris May 15, 2008 to protest against job cuts and reforms announced by France's President Nicolas Sarkozy's government. The placard reads, "High school students on strike".

Teachers and students marched through central Paris in a demonstration that flowed through some of the French capital's biggest boulevards. Police estimated the number of marchers at 18,000 while organizers put the figure at more than 50,000.

The main issue in Thursday's protests was a plan to shed 11,200 jobs in education, including over 8,000 teaching posts, by not replacing one out of two retiring employees.

The government says the job cuts are necessary to rein in public spending and balance the budget by 2012, in line with a French commitment to the European Union.

An OpinionWay poll found 54 percent of respondents felt the strike was justified.

Sarkozy, whose popularity ratings are at record lows, said in a televised speech he supported the right to strike but would push for a law forcing schools to stay open during strikes so parents can go to work.

"Strikes bring insurmountable difficulties to many families... I have asked the government to submit a bill before the summer to guarantee a right for children to be received at our schools," he said.

FISCAL GIFTS

The education ministry said 34 percent of its employees, or almost 300,000 people, were on strike as of noon. Teacher unions gave higher figures, saying a majority had taken part and that the strike was bigger than a previous walkout last March.

At the main demonstration in Paris, dozens of trucks loaded with sound systems and balloons headed across the Seine river. One banner read: "For education -- act without moderation."

"If the government needs money, it should repeal Sarkozy's tax cuts for the rich, " said Leonore Topelet, 16.

Education Minister Xavier Darcos refused to back down despite the protests and criticised the strike call.

"These methods are not adapted to the problems we are facing today," he told LCI television.

But protesters in Paris were convinced the government could make savings elsewhere to keep its budget pledges.

Olivier Besancenot, a rising star on the far-left who plans to found a new 'anti-capitalist' party this year, agreed.

"We should cut back on fiscal gifts and subsidies for big companies, and we don't need to be sending more troops to Afghanistan," he said as students asked for his autograph.

Air traffic controllers in Marseille also joined the protest movement, causing a delay of between one and 1-1/2 hours to flights into and out of the southern city's airport, a spokeswoman for France's civil aviation authority said.