The two-round presidential election is set for April 23 and May 7.
Mr Melenchon and the 10 other presidential candidates appeared on a television programme on Thursday night where they are scheduled to speak one after another.
PARIS French presidential candidate Emmanuel Macron spoke with former USA president Barack Obama on the phone on Thursday, in an apparent sign of support just three days before the first round of an uncertain presidential election.
That's because one of the leading candidates, far-right nationalist Marine Le Pen has pledged that should she win the presidency, France will go the way of the United Kingdom and exit the European Union. Francois Fillon, right, former French Prime Minister, member of the Republicans political party and 2017 French presidential election candidate of the French centre-right, is greeted by supporters as he arrives t. "Are we going to be able to live as French for much longer when entire neighbourhoods are taken over by foreigners?" she said to wild applause and cheering.
The new hardline tack has gained approval from her fans, with many at the Marseille rally chanting "la France aux francais" (France for the French), an old slogan associated with the xenophobia and anti-Semitism that infected the Front National when it was led by Mr Le Pen.
Gaspard Flamant, 26, said he feared Le Pen could win. In Marseille. She reiterated her plan to expel all foreigners in a suspect file and strip dual national suspects of their French nationality.
The polls have four candidates - centrist Emmanuel Macron, conservative Francois Fillon and communist Jean-Luc Melenchon - neck and neck within the margin of error. Hamon, the Socialist, trailed in fifth. She said Wednesday that "I am a candidate in the election for the French republic" and said Europe is acting like France's "enemy".