PARIS (Reuters) - The top candidates in France's volatile presidential election go head-to-head in a televised debate on Monday as polls show centrist Emmanuel Macron and far right leader Marine Le Pen pulling away from the pack five weeks before the first round.
Macron, Le Pen and the three other leading candidates will take part in a nearly three-hour debate on the main private channel starting at 9 P.M. (2000 GMT) on Monday evening expected to be watched by millions.
The televised debate, the first held before the first round of a French presidential election, may be crucial in helping viewers make up their minds.
Opinion polls show almost 40 percent of voters are not completely sure who to back in the election, being held over two rounds on April 23 and May 7 against a backdrop of high unemployment and sluggish growth.
Markets, surprised by Britain's Brexit vote last June, are nervous about the possibility of a victory by National Front leader Le Pen, who pledges to take France out of the euro and hold a referendum on EU membership.
Polls show Macron and Le Pen establishing a clear lead in terms of voting intentions in the first round, while conservative candidate Francois Fillon, the one-time front-runner who has been damaged by a financial scandal, has slipped back.
An attack at Paris Orly airport on Saturday, when a man known to police as a radicalized Muslim was shot dead after trying to grab a soldier's rifle, has put security back in the spotlight after a series of Islamic attacks shook France.
That could play into the hands of right-wing candidates Le Pen and Fillon, who advocate tougher security measures.
The latest daily Opinionway poll on Monday showed Le Pen scoring 27 percent in the first round, in front of Macron on 23 and Fillon on 18. Only the top two candidates go through to the run-off, when polls suggest Macron would easily beat Le Pen.
The premium that investors demand to hold French instead of German debt rose to its highest in almost two weeks on Monday, reflecting unease among investors before the debate.
"We think the importance of this debate should not be underestimated. Only 60 percent of voters polled by Ifop say they have made up their mind," said Mizuho rates strategist Antoine Bouvet.
Pollster Ifop's data show more than 80 percent of Le Pen's backers saying they would definitely vote for her in the first round. By contrast, less than 49 percent of Macron's supporters were certain they would vote for him.
The other two candidates taking part in Monday evening's debate are the ruling Socialist Party's candidate Benoit Hamon and Jean-Luc Melenchon, who have split the left-wing vote.
Macron, 39, a former economy minister and investment banker who has never run for elected office, made a name for himself by criticizing sacred cows of the French "social model" such as the 35-hour working week, iron-clad job protection and civil servants' jobs for life. Other candidates are likely to attack his relative inexperience.
(Reporting and writing by Adrian Croft; Editing by Richard Balmforth)