French election race tightening three weeks from vote, poll shows

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First round voting intentions for the frontrunners, centrist Emmanuel Macron and far-right leader Marine Le Pen, both slipped by one percentage point to 25 and 24 percent respectively, while third placed conservative Francois Fillon gained two points to 19 percent, and the far left's Jean-Luc Melenchon one point to 15 percent, the BVA poll said.

Marine Le Pen, French National Front (FN) political party leader and candidate for French 2017 presidential election talks to the media during a visit to a market in Concarneau, France, March 31, 2017. REUTERS/Stephane Mahe

In a further signal of continued unpredictability, 38 percent of people either could not say how they would vote, or may yet change their minds. That was down two percentage points from a week earlier, but still a high percentage by French election standards.

The poll showed independent Macron had solidified his voter base, with 63 percent of those opting for him sure of their decision, up 8 points from a week ago and his highest certainty score since campaigning began in earnest in February.

However, Le Pen still had by far the most solid voter base, with an unchanged 81 percent of her voters certain to pick her.

Shock outcomes like the election of Donald Trump as U.S. president and Britain's Brexit referendum vote have fed expectations that Le Pen's anti-euro, anti-immigration platform will sweep her to power in France.

The poll though, like others this year, showed Macron beating her with 60 percent of votes in the May 7 second round.

Fillon's recovery from the lows that followed a fake work scandal surrounding his wife puts him within 5 points of Le Pen and 6 points of Macron, with some voters previously tempted to abstain deciding to go for him after all, BVA's commentary said.

BVA put Melenchon's climb since a strong performance in the first TV debate on March 20 partly down to more of his natural sympathizers deciding to vote.

However it noted that official Socialist candidate Benoit Hamon, who is in fifth place on 11.5 percent and also has hard left policies, could be vulnerable.

Hamon's base of sure voters is just 45 percent, it noted, and many of them could end up being split - about equally - between Melenchon and Macron.

An Odoxa survey on Friday showed Melenchon just one percentage point behind Fillon on 16 percent, but 8 points ahead of Hamon.

The Odoxa poll was is the first to suggest a dynamic in which France's two-party system that has been in place for 30 years alternating between the Conservatives and the Socialist party could be swept aside.