Addressing around 3,000 party faithful in the town of Frejus on the Cote d'Azur, Le Pen aimed to set the tone for her campaign, declaring in her speech: “The time of the nation state has come again.”
The FN leader, who has pledged to hold a referendum on France's future in the EU if elected and bring back the French franc, said she was closely watching developments in Britain since it voted to leave the bloc.
“We too are keen on winning back our freedom…. We want a free France that is the master of its own laws and currency and the guardian of its borders.”
Polls consistently show Le Pen among the top two candidates in the two-stage presidential elections to take place in April and May.
But while the polls show her easily winning a place in the run-off they also show the French rallying around her as-yet-unknown conservative opponent in order to block her victory in the final duel.
In Frejus, Le Pen sought to sanitise her image, continuing a process of “de-demonisation” that has paid off handsomely at the ballot box since she took over the FN leadership from her ex-paratrooper father Jean-Marie Le Pen in 2011.
“I am the candidate of the people and I want to talk to you about France, because that is what unites us,” the 48-year-old politician said in a speech that avoided any reference to the FN which is seen as more taboo than its leader.
She also avoided any attacks on her rivals, preferring to remain above the fray as her arch-nemesis, former president Nicolas Sarkozy, and other candidates battle it out for their parties' nominations.
Le Pen said French voters were never given a say on the “biggest change in a century in the nation: the opening up to mass immigration”.
Immigration, she said, had “swept aside the benefits of secularism, women's liberation and the Republican pact”, bringing in “people with beliefs, customs and practises that are not ours”.
Her speech was regularly interrupted by her supporters chanting “On est chez nous” (“This is our land”) and waving French flags.
But she devoted relatively little time to the FN's stock themes of Islam and national identity, focusing instead on sovereignty.
Accusing foreign masters in Brussels, Berlin and Washington of calling the tune in France, she called for greater protectionism and “economic patriotism” to restore World War II hero General de Gaulle's vision of a “free France”.
Analysts say Le Pen's more inclusive approach is aimed at taking the fear factor out of a National Front presidency.
They have attributed her relative silence on the jihadist attacks of this summer — contrasting with Sarkozy's glut of hardline declarations on national identity and security — to her attempt to appear “presidential”.
Former prime minister Francois Fillon, who is one of Sarkozy's challengers for the presidential nod of the Republicans party, rejected the notion that the FN had changed.
“Everyone sees the FN, with its absurd economic policy and its positioning which incites confrontation and hate,” Fillon told Europe 1 radio, insisting:
“It's a far-right party.”