PARIS - France's presidential candidates made their final pushes for votes as polls Thursday pointed to a cliffhanger among the top four hopefuls, led by conservative Nicolas Sarkozy and Socialist Segolene Royal.

Royal took heart from polls showing that millions of voters have not firmly decided whom they will back in Sunday's first-round vote that will whittle down the field from 12 total candidates to two for a decisive May 6 runoff.

"Everything is open," Royal told RTL radio. Polls "indicate that there are still 17 million voters who haven't decided yet."

A poll for Le Figaro newspaper showed Sarkozy, the nominee for President Jacques Chirac's governing party, drawing 28.5 percent of votes for the first round. Royal tallied 25 percent. But the margin of error in surveys of its size is plus or minus three percentage points, meaning that statistically, they are in a dead heat.

Still trailing -- but gaining ground -- were centrist Francois Bayrou at 19 percent and far-right nationalist Jean-Marie Le Pen at 14 percent, according to the poll.

However, the daily Ipsos poll for Le Point magazine showed a widening gap between the two front-runners, putting Sarkozy at 30 percent and Royal 23.5 percent -- with Bayrou holding steady at 18.5 percent and Le Pen dropping slightly to 13 percent. Its margin of error was also around plus or minus three percentage points.

The Le Figaro survey said that only 54 percent of voters were fixed in their choice with only three days to go, increasing speculation about which two candidates will qualify for the decisive runoff.

Candidates are required to stop campaigning by midnight Friday.

Royal sought to prop up her base Thursday after several Socialist Party elders -- nicknamed the "elephants" -- suggested she could not win alone and that she strike some sort of alliance with Bayrou to keep Sarkozy out of office.

"I'm keeping my calm and inner strength," said Royal, aspiring to become France's first woman president, on RTL radio. "Some elephants haven't done everything to simplify my task ... some of them still have trouble accepting my nomination."

Sarkozy trained his fire against Bayrou, a longtime center-right politician who has recast himself as a national unifier who wants to bridge France's left-right divide. Most polls show that Bayrou is the only candidate who could defeat Sarkozy if he made it to the runoff.

"I knew him for years as a man of the right. For some time now, he's been changing and has become the candidate of the left," Sarkozy said, referring to Bayrou. "The only question is: Did he ask voters if they agree?"

The telephone poll of 1,000 registered voters by TNS-Sofres for Le Figaro, LCI television and RTL radio was conducted Monday and Tuesday. The Ipsos poll of 1,212 registered voters for Le Point took place by phone Tuesday and Wednesday.