PARIS (Reuters) - The lone centrist in France's presidential election, Francois Bayrou, is weighing whether to hitch his wagon to a struggling conservative Nicolas Sarkozy before the second round or stick to his principles and stay in opposition, analysts say.
The deciding factor will be whether Sarkozy has any chance of seizing the final round on May 6 from Socialist Francois Hollande, they say, with surveys indicating the challenger 8 to 16 percentage points ahead of the incumbent.
Credited with about 10 percent of Sunday's first round vote, Bayrou could still be a kingmaker for Sarkozy if he can persuade enough of his swing voters to veer right in the runoff.
"It's time for Sarkozy to make an overture," said Mariette Sineau, a political scientist at the CEVIPOF research centre.
The beleaguered president, who latest polls shows trailing Hollande by a growing margin, appeared to drop a hint to the centrist in a radio interview on Wednesday.
Asked whether he might offer the premiership to Bayrou between the two rounds, Sarkozy told RMC radio he wanted to see the first ballot results but he had "a pretty clear idea".
Bayrou poured cold water on the notion on Wednesday, saying: "The idea that I could lend myself to that kind of maneuver comes from people who are totally unaware of my political course and, to use a big word, of the true me."
Presidential allies have made other overtures to Bayrou in the media over the past week and Sarkozy himself has said Bayrou's views on balancing public finances mirror his own.
Foreign Minister Alain Juppe called the centrist a possible candidate for prime minister. Bayrou has branded that comment "electioneering" but did not explicitly reject the idea.
The centrist has so far kept mum about who, if anyone, he will support, although he did say last year he would express a preference, unlike in the 2007 presidential election.
A leading role in a second-term Sarkozy government could be tempting, enabling Bayrou to secure a parliamentary group for the centrists, who lost most of their seats in 2007, and extract concessions on fiscal policy and electoral reform.
But the candidate will not want to risk an alliance if a Sarkozy victory seems too unlikely, Sineau said.
"He's at a political impasse," she said. "He's stuck."
Some analysts think Bayrou may keep silent or give Sarkozy only a cursory nod, preserving his own political integrity and placing himself to pick up the pieces if the president loses.
Experts say he may well be counting on a post-Sarkozy breakup of the ruling centre-right UMP party, which could lead to the emergence of a large moderate bloc in which Bayrou would expect to be a major player.
"If Sarkozy loses and the right implodes, there is a chance for him to become a political leader and put together a team. That's plausible," said Celine Bracq of pollster BVA.
Furthermore, Bayrou risks antagonizing his base if he backs Sarkozy, who has swung to the right on sensitive issues for pro-European, libertarian centrists such as immigration, the European Union's open border policy and civil liberties.
"To support Sarkozy just before the second round after only recently describing him as 'unfit to embody the presidency,' ... that's a real question mark," Bracq said.
As Sarkozy's momentum has faded in the last 10 days, Bayrou has failed to make headway.
A three-time candidate, his oft-repeated message of fiscal responsibility seems to tire the French, while hard leftist Jean-Luc Melenchon and far-rightist Marine Le Pen have captured the anti-establishment mood and injected energy into the race.
"For an electorate, it's not exactly a motivating campaign argument to say, 'We have to reduce the debt,'" said Sineau.
Complicating Bayrou's decision on whether or not to support Sarkozy are the preferences of his supporters. Some 44 percent are leaning towards Hollande in the second round, versus 29 percent for Sarkozy, a BVA survey showed. They might not follow him if he endorsed the president.
"If he clearly sides with Sarkozy in the hope of eventually being prime minister, it could be a gamble," said Bracq.
A reporter tried to get Bayrou to tip his hand by asking whether his plans to revive industrial production in France would be more easily accomplished if he were prime minister.
"I assert without the slightest doubt that it would be more effective, and quicker, if I were president," Bayrou deadpanned.
Editing by Paul Taylor