France's volatile presidential campaign wound down Friday with conservative Nicolas Sarkozy still the favorite to advance to a final runoff. But, with two in five voters hesitating about their choice, the race for the second spot on the ballot was wide open.

All 12 candidates were required to halt campaigning by midnight. Early voting begins Saturday in some French overseas territories, with mainland France casting ballots Sunday. A runoff between the top two contenders is planned for May 6.

The election will determine who leads a nuclear-armed nation with a permanent seat on the U.N. Security Council after 12 years under President Jacques Chirac.

Sarkozy, like German Chancellor Angela Merkel, is often perceived as pro-American. Such a duo in charge of the governments in Paris and Berlin would signal change from the era of Chirac and former Chancellor Gerhard Schroeder — who had chilly relations with Washington, mainly over the Iraq war.

France is looking for new direction, down on its economic fortunes, adrift in its identity, and still coping with fallout from youth riots in poor, immigrant areas in 2005.

A poll released Friday by TNS Sofres Unilog said Sarkozy would garner 28 percent Sunday, followed by the Socialist Segolene Royal at 24 percent and center-right hopeful Francois Bayrou at 19.5 percent. Ultra-right leader Jean-Marie Le Pen came in at 14 percent.

An Ipsos poll put Sarkozy at 30 percent, Royal at 23 percent, Bayrou at 18 percent and Le Pen at 13 percent. Both showed the rest of the field tallying low single-digit percentages.

In the runoff, TNS Sofres' poll said Sarkozy would win with 53 percent, compared with Royal's 47 percent; Ipsos had Sarkozy at 53.5 percent and Royal at 46.5 percent. Those agencies polled between 1,000 and 1,200 adults this week. Polls of such size usually have a margin of error of plus or minus 3 percentage points.

Forty-two percent were toggling between two or three candidates or entirely uncertain, TNS Sofres said. Ipsos did not calculate such data, but said that only 55 percent of supporters of Bayrou were firm about their choice of him — the lowest tally among the four leading contenders to make the second round.

Frederic Daby, a director of the IFOP polling agency, said there were two main camps of undecided voters: one choosing between Sarkozy and Le Pen, the other between Royal and Bayrou.

"It's entirely possible that we have one or two big surprises, because we've rarely had such a high undecided rate," he said. "It's not undecided in the sense of 'I don't care about politics' or 'I'm not sure' — there are just a lot of people hesitating."

In 2002, in the last presidential vote, voters disaffected by the political establishment flocked to Le Pen and he advanced to the run-off against Chirac. He lost, but his ability to even make it that far shocked many.

Voter registration is up everywhere, especially in poor suburbs where largely Muslim and African immigrants and their French-born children live in forgotten housing projects — and up to half the youth are jobless.

The second round was shaping up as a referendum on Sarkozy — a figure of discord. His frankness, energy and free-market values are adored on the right, but his tough talk against suburban troublemakers has gone down badly with many immigrants' children.

The left fears that his years as a tough interior minister — France's top cop — make him ill-suited for the job as its top diplomat, and the wrong answer for millions of people worried about job security.