"I propose that the National Front become the National Union (Rassemblement National)," Le Pen told an annual conference of members in the northeastern city of Lille. "But it's you who will vote on it, it's you who will decide."
The 49-year-old unveiled the party's new identity at a meeting in the northeastern city of Lille, aiming to bury the National Front (FN) name that has been associated with her father Jean-Marie since 1972.
The switch is meant to signal a new beginning for the anti-immigration movement -- and a decisive break from the toxic past of Jean-Marie who was finally banished from the party on Sunday.
Le Pen scored a lower-than-expected 34 percent as she lost to President Emmanuel Macron last May and has since struggled to assert her authority after admitting to mistakes during her campaign.
"Without a name change, we will not be able to forge alliances. And without alliances we will never be able to take power," she said last month as she faced questions from many sceptical members.
Le Pen had kept the new name a closely-guarded secret, although "Rassemblement National" (national union) had been mooted as an option.
Le Pen won a major boost on Saturday from former Donald Trump aide Steve Bannon who appeared alongside her at the National Front conference and told delegates that "history is on our side".
Bannon's appearance reinforced the links between the Trump campaign and France's far-right party which hold similar views on immigration, Islam, trade, the European Union and Russia. Trump came close to endorsing Le Pen as she sought to defeat Macron last year.
"Let them call you racists, let them call you xenophobes, let them call you nativists. Wear it as a badge of honour. Because every day we get stronger and they get weaker," Bannon told the audience.
The presence of the former head of Breitbart News drew a stinging response from Macron's government.
"The king of fake news and of white supremacists at an FN summit... why am I not surprised?" remarked parliamentary affairs minister Christophe Castaner, who is also the head of Macron's centrist Republic on the Move party. "Change of name but not of the political line."
Le Pen's bid to change the party's name does not have unanimous support at the grassroots level and has been heavily criticised by Jean-Marie, who sees it as an attack on his legacy.
The party canvassed 51,000 members last year about the new name proposal and on Saturday it emerged that just 52 percent had voted in favour among the 30,000 who responded.
That compared with 90 percent of respondents wanting a referendum on continued EU membership and 98 percent wanting to cut immigration to France. Speaking on Saturday, FN youth leader Gaetan Dussausaye admitted the party had to "swallow its pride" as "the FN brand is still a block for voters".
The National Front was co-founded by Jean-Marie Le Pen in 1972 and led by him for nearly 40 years until he was replaced by his daughter Marine in 2011. She attempted to banish him from the party in 2015 after he repeated his belief that the Nazi gas chambers were "a detail of history".
The party voted to strip him of his role as honorary president on Sunday.