French far-right leader Marine Le Pen hailed her score in presidential elections on Sunday as a "brilliant victory", despite her projected defeat to Emmanuel Macron.

Promising to "carry on" her political career, the 53-year-old vowed that she would "never abandon" the French after losing with around 42 percent of the vote to Macron's roughly 58.

"The ideas we represent have reached new heights... this result itself represents a brilliant victory," she told a crowd of supporters at an election-night party.

She joined other challengers eliminated in the first round in calling for a new effort to hinder the president's second term at June parliamentary polls.

Promising to 'carry on' her political career, the 53-year-old vowed that she would 'never abandon' the French after losing with around 42 percent of the vote
Promising to 'carry on' her political career, the 53-year-old vowed that she would 'never abandon' the French after losing with around 42 percent of the vote AFP / Christophe ARCHAMBAULT

"This evening, we launch the great battle for the legislative elections," Le Pen said, saying she felt "hope" and calling on opponents of the president to join with her National Rally (RN) party.

Both candidates had sought to rally supporters of hard-left chief Jean-Luc Melenchon to their side in the second-round run-off, after he came close to edging Le Pen out of the showdown with incumbent Macron.

Le Pen managed to win over a razor-thin majority of working-class voters to her cause, an election-day survey of almost 6,000 people by pollsters Opinionway found, while Macron enjoyed a comfortable lead among other social categories.

Her strong showing Sunday was another illustration of the erosion of the traditional "republican front" of mainstream voters against France's far right.