The election will begin on April 23, taking place across two rounds.
Sunday's vote is round one of two.
The candidates for France's first-round presidential election Sunday have increased security in recent days.
Demonstartors march behind a banner as they stage a protest against the far-right Front National (FN) in Marseille on April 19, 2017 in a reszponse to the campaign meeting in the city of the French presidential election candidate for the Front National (FN) party Marine Le Pen.
Hamon won the Socialist primary but the party is deeply divided, and Socialist President Francois Hollande is so unpopular that he's not seeking a second term.More news: US VP Mike Pence meets Indonesian president on Asia tour
But, she said, her first job as president would be to pull France out of the borderless Schengen agreement and give the nation back its borders, which she called a "sieve" for the entry of terrorists who she said travel Europe like tourists.
Tf1 guests normally appear beside an European Union flag tethered to a French tricolour but, unlike rival candidate Emmanuel Macron, Ms. Le Pen insisted that only the French flag should feature alongside her. France's presidential candidates certainly think they do, and more than ever are trying to get their political message across through their wardrobes, from centrist Emmanuel Macron's regular-guy suits to far right leader Marine Le Pen's masculine dark wardrobe and hard-left Jean-Luc Melenchon's communist-inspired jackets.
Macron, a former banker who quit as economy minister last August to set up his independent "En Marche!" or "Onwards!" movement, would beat Le Pen or any other candidate in the run-off, the Harris poll showed. "Well, France is not for sale, the French people are not for sale", she said.
Ms Le Pen said she only wanted the French flag behind her in the shot.