Paris ? President Nicolas Sarkozy’s party won a clear parliamentary majority Sunday in elections seen as crucial to his vision for opening up France’s economy, although the opposition thwarted a landslide victory by capitalizing on voter fears of giving Sarkozy too much power.

Sarkozy’s UMP party will face little resistance to the rash of measures he plans to introduce within weeks to make France’s sluggish economy more competitive and less protective.

But Sunday’s legislative runoff suggests that voters in France, long driven by leftist ideals, wanted to send the hard-driving and U.S.-friendly president a message that his powers are not absolute, and to keep their concerns in mind.

Some have even predicted mass street protests – like those that stymied former President Jacques Chirac’s efforts to free up the economy – or an eruption of violence in France’s housing projects if Sarkozy goes too far, too fast.

“The French showed they did not want to give all of the power to Nicolas Sarkozy,” former Justice Minister Elisabeth Guigou, a Socialist, said Sunday night.

Sarkozy’s party and its allies won 346 of the 577 seats in the National Assembly, which was fewer than the 359 seats the UMP used to have. The opposition left took a better-than-expected 226 seats total, led by the Socialists’ 185 seats – a considerable improvement to the party’s 149 seats in the last parliament.

Socialist Party leader Francois Hollande said that his party had resurrected itself. “It’s good for the country,” he said. “France will walk on both legs.”

It marked the first political stumble for the 52-year-old Sarkozy since he was elected president last month. In another blow to the new president, environment and energy minister Alain Juppe lost his race to a Socialist challenger and announced that he would resign Monday, meaning Sarkozy faces the prospect of reshuffling his month-old government.

Last week’s first round of voting had left the Socialists expecting just more than 100 seats, while the buoyant UMP was looking forward to the strongest parliamentary majority in the history of modern France.

Then, in just seven days, the Socialists tapped into fears of a rubber-stamp parliament for Sarkozy and worries about a 5-percent sales tax increase, intended to finance social programs.