"Nationalism is war. … You are taking out, sorry to tell you, the lies that we have heard for forty years, and we heard [them] from your father," Macron said.
Macron was speaking at the debates that brought together all 11 French presidential candidates, televised by the BFMTV broadcaster.
The first round of the French presidential elections will take place on April 23, while the run-off between the top two contenders is scheduled for May 7.
The National Front (FN) party, established in 1972, sticks to the values of nationalism, anti-immigration policy, protectionist measures in economy and opposes multiculturalism. The FN has long been associated with the name of its former leader Jean-Marie Le Pen known for controversial statements on Nazi gas chambers used to kill people during the World War II and considered as a xenophobe.
In 2011, Jean-Marie was succeeded by his daughter Marine, who has initiated a campaign to "de-demonize" the image of the party and to get rid of the controversial legacy of her father. Marine Le Pen has also made a number of statements that have been criticized by several political powers in France, such as the need to introduce new taxes on contracts with foreign workers.