The fiery leader of France's far-right, Marine Le Pen, looks set to take a decisive step on Sunday towards winning control of a region for the first time, while her niece is in a strong position to do the same elsewhere in the country.

Polls show that Le Pen's National Front (FN) could take a commanding lead in the northern region of Nord-Pas-de-Calais-Picardie in the first round of regional elections, feeding off discontent with the ruling Socialists and fear after the jihadist attacks in Paris.

Victory in the second round on December 13 would give the FN control of a region for the first time in its history.

Control of the economically depressed region -- traditionally a bastion of the Socialists who rule at national level -- would also provide Le Pen with a springboard for her bid to be president in 2017.

Meanwhile, her 25-year-old niece   could lead the FN to victory in the vast Provence-Alpes-Cote-d'Azur (PACA) region in the south, according to polls Friday.

Marine Le Pen, who cast her vote Sunday morning, was never supposed to inherit the party from its founder, her father Jean-Marie Le Pen, who rocked the French 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 was expected to take over the role.

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

A lawyer by training, she eventually took over the reins in 2011 and swiftly set about giving the FN "a different image to the stereotype".

She 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.

- 'Send them back' -
But Marine is still capable of the coarse political discourse that is her father's trademark.

She told reporters earlier this year that there was a simple way to deal with the flow of migrants arriving in Europe: "Feed them, warm them up, and send them back where they came from."

Marine has also been 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.

It led to Le Pen senior being thrown out of the party he founded this summer. He and his daughter have not spoken since.

But with the attacks in Paris, his daughter was able to turn attention away from the Le Pen 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.

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

Yet many observers believe it is her photogenic niece Marion who is the real ideological heir of Jean-Marie Le Pen.

Her ultra-conservative views often position her to the right of her aunt.

On Tuesday, Marion said Muslims could only be French "if they follow (our) customs and way of life".

Her rise has been rapid. She stood -- unsuccessfully -- for regional elections in 2010 and famously cracked when a reporter asked her to outline policy areas she wanted to address, unable to provide a single example.

But since becoming an MP, and a mother for the first time, Marion has gone through an astonishing transformation, building a growing following among young radicals and older party supporters disgruntled with her aunt.

She had no qualms in standing up in the lower house National Assembly and accusing a visibly furious Prime Minister Manuel Valls of "moronic contempt" towards the FN.

She also joined the ranks of anti-gay marriage protesters in 2013 when Marine decided to stay away.
Source: AFP