A fiery orator but also a pragmatist, Marine Le Pen has steered France's far-right National Front (FN) from pariah status into the mainstream.

Despite her party's defeat in regional elections on Sunday, she sounded a typically defiant and vitriolic note, lashing out at the traditional parties for teaming up against her and vowing to press on.

"Nothing can stop us now. Election after election, the rise of the nationalist tide is inescapable," she thundered to downcast supporters after the initial results were released.

The first round of the regional elections had given the anti-immigration FN the highest share of the vote, bolstering Le Pen's claim to lead "the first party of France".

Since inheriting the party in 2011 from her rabble-rousing father, Jean-Marie Le Pen, she has gone to great lengths to "de-demonise" its image.

But Sunday's results showed the 47-year-old lawyer by training still has some way to go before convincing the majority of French voters that her party is no longer a collection of dangerous extremists.

In the northern Nord-Pas-de-Calais-Picardie region, she broke the symbolic 40-percent mark in the first round on December 6, exploiting anger over the dismal economy and the large numbers of migrants camped out in squalid conditions as they try desperately to reach Britain.

But as so often for the FN, it was trounced in the second round after the ruling Socialists withdrew candidates and urged voters to back the centre-right.

Marine, as she is commonly known, still sees the regional polls as a springboard for her run at the presidency in 2017.

- Thrust into limelight -

She was never meant to inherit the party from her father, the former paratrooper who rocked the establishment by reaching the second round of the presidential election in 2002 at the expense of Socialist Lionel Jospin.

It was Marine's older sister, Marie-Caroline, who had been groomed to take over the helm.

But the FN's brutal internal politics and family splits saw Marine propelled into the limelight instead.

Eschewing the nakedly xenophobic and controversial outbursts of her father, she set about broadening the party's appeal by focusing on opposition to the European Union and immigration -- two themes that struck a chord, particularly outside the big cities, at a time of economic downturn.

She also sought to purge the worst of the anti-Semitic elements as well as the fundamentalist Catholics who for three decades had been one of the main strands of the party leadership.

Twice-divorced and a mother of three children, she has also broken with the party's past by promoting several gay advisors into her inner circle.

Her makeover of the party was hit by a very public rebellion within her own family.

Her father, now 87, was clearly unhappy with the direction in which she was taking the party and sought to undermine her with a string of anti-Semitic diatribes.

Earlier this year, it led to Le Pen senior being thrown out of the party he founded and he and his daughter are said not to have spoken since.

But with the November 13 attacks in Paris, Marine was able to turn attention away from the family soap opera and declare that the Western world had "no choice but to win the war" against the attackers from the Islamic State group.

It played into the Islamophobic themes that have never been far from the FN's surface.

"If we fail, Islamist totalitarianism will take power in our country," she said.

But despite a broad disillusionment with the two main parties, that have both failed to kickstart the French economy in recent years, too many voters still worry about putting a far-right government in power.

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