Supporters of Mr. Macron, who styles himself as a progressive transcending France's entrenched left-right divide, are among the most volatile while Ms. Le Pen's are the most loyal, polls show.
Macron reacted furiously when Le Pen accused him of backing the burkini, suggesting he wasn't really committed to France's secular approach.
Le Pen, among the frontrunners in the French presidential election, travelled to Lebanon in February to get a sense of the Syrian crisis and is using the two-day visit to meet French troops stationed in Chad and outline her policies for Africa.
In the fiery encounter between the top five contenders, Ms Le Pen said: "I want to stop immigration, it is clear".
Setting out her vision of a France which defends its interests "without being lectured by a supranational body", Le Pen, who has accused Germany of dictating to the rest of Europe, said: "I have no desire to be Mrs Merkel's deputy".
The markets have been nervous about the possibility of a Le Pen victory as she has pledged to take France out of the euro and hold a referendum on European Union membership.
"The burkini is a public order problem".
The moves came after an Elabe poll (https://twitter.com/elabe_fr/status/843978193161932800) showed 29% of viewers who watched Monday's night debate thought Macron was the most convincing candidate (http://www.marketwatch.com/story/frances-presidential-upstart-macron-clashes-with-le-pen-fillon-in-tv-debate-2017-03-21) to become the next president.
"That's called Project Fear, Mr Fillon".
In addition, the European Central Bank's ongoing targeted long-term refinancing operations (TLTRO) - where it lends money to euro zone banks at extremely low funding costs - may have also had an effect.
She said: "We have seven million unemployed people, nine million suffering from poverty".
Six other candidates were excluded according to Le Monde newspaper: Nicolas Dupont-Aignan, Nathalie Arthaud, Philippe Poutou, Jacques Cheminade, Jean Lassalle, Francois Asselineau.
A total of 11 candidates are running for president.
Neither Le Pen not the Chadian government have commented on the reports.
French voters will go to the polls on April 23 for the first round of the elections and on May 7 for the second.
The trained lawyer has worked hard to purge the National Front of the anti-Semitism and overt racism bequeathed by her father.