PARIS - French President Nicolas Sarkozy may shuffle his nascent government following the defeat of the No. 2 Cabinet official in weekend parliamentary elections, contests that gave him a comfortable majority but not the crushing victory predicted in polls.

Sarkozy confirmed Prime Minister Francois Fillon as prime minister in a meeting Monday, a formality. But as early as Tuesday he was expected to add, as promised, up to 10 junior ministers, including some from the leftist opposition and others to reflect France's "diversity."

He could also shuffle the Cabinet to replace Ecology Minister Alain Juppe, although one minister publicly questioned whether the president would follow through with an order to get rid of any minister who lost his parliamentary race.

Despite surprising gains by the fractured left, Sarkozy, in office since May 16, emerged from Sunday's runoff elections as a singularly strong leader, with the government, parliament and top state bodies all under the control of his conservative parties. It was the first time since 1958 that an outgoing majority has replaced itself.

Still, Sarkozy's government is likely to face legislative fights it was not counting on to push through a rash of reforms it plans to introduce within weeks to rejuvenate a morose France.

Sarkozy's UMP party and its allies got 346 of the 577 seats in the National Assembly, parliament's lower house. That is fewer than the 359 UMP seats in the outgoing parliament.

The opposition left secured a better-than-expected 226 seats, led by the Socialists with their 185 seats -- a considerable improvement on the party's 149 in the last parliament.

The 52-year-old Sarkozy hopes to use his power at home to help revive a hobbled Europe at a two-day summit that opens Thursday in Brussels, pushing his plan for a simplified treaty to replace the EU constitution rejected by the French and the Dutch in 2005.

On the homefront, Sarkozy received the prime minister less than 12 hours after final election results were tallied, formally returning him to his post. The fate of Juppe, the government's No. 2, initially considered sealed, was thrown into doubt Monday with comments by one minister.

In one of the electoral shocks, Bordeaux Mayor Juppe offered his resignation Sunday night after losing his parliamentary race -- in keeping with a rule set by Fillon encouraging ministers to run and to lose their Cabinet posts if they lost the vote.

However, Public Policies Minister Eric Besson said the resignation rule "is not automatic" and that Sarkozy is "capable" of skirting it.

"Nicolas Sarkozy is capable of transgression on a certain number of subjects. He could do so on this point," Besson told BFM TV.

Juppe's resignation "is a loss for the government and probably for our country," Besson said.

The conservative daily Le Figaro raised the possibility that Finance Minister Jean-Louis Borloo could replace Juppe with the finance post filled by AXA insurance company chief executive Henri de Castries.

The impressive comeback of the opposition Socialists, given up for nearly dead just days ago, surprised even the party, which campaigned on the fear factor of an all-powerful Sarkozy and hints that he could quickly raise a sales tax.

Analysts cited the tactic for the success that defied poll predictions.