France was voting in a regional election on Sunday in a poll widely-expected to see the far-right National Front edging towards historic gains just three weeks after Islamic extremists attacked Paris, killing 130 people.
Around 44 million people are eligible to vote in a poll being held in tight security following the country's worst-ever terror attacks, which have thrust the FN's anti-immigration and often Islamophobic message to the fore.
First projections are expected at 1900 GMT with FN leader Marine Le Pen on course to top the poll in the economically-depressed northern region of Nord-Pas-de-Calais-Picardie, which was once a bastion of the left.
And her 25-year-old niece Marion Marechal-Le Pen seems to be heading for an equally strong score in the vast southeastern Provence-Alpes-Cote d'Azur region that includes beaches thronged by sun-seekers in the summer.
"I expect to gain enough momentum in this first round to be optimistic about the second round," Marine Le Pen said as she cast her vote on Sunday morning.
By midday (1100 GMT), turnout remained low at just over 16 percent.
Casting his ballot in Evry south of Paris, Prime Minister Manuel Valls urged voters to get out and cast their ballots, describing the election as a key part of the fight against terror.
"I hope many French people will vote, especially after the terrorist attacks. We shall overcome, and our weapon is our vote," he said.
President Francois Hollande, who cast his vote in Tulle in central France, has seen his personal ratings surge as a result of his hardline approach since the November 13 Paris attacks.
But his Socialist party is languishing behind the FN and the centre-right Republicans led by former president Nicolas Sarkozy, .
The FN is also expected to compete for power in the eastern Alsace-Champagne-Ardennes-Lorraine region that borders Belgium and Germany, according to polls by Ipsos and Odoxa.
Analysts predict the FN could take all three regions in the second round on December 13 -- if traditional parties refuse to join forces against them.
Victory would not only put the party at the head of a regional government for the first time, but would also give Marine Le Pen a springboard for her presidential bid in 2017.
In her campaign, she has focused repeatedly on the migrant camp in Calais, 'the Jungle', where thousands of people have been camped for months trying to reach Britain and northern Europe.
With the FN also locked in a close race for Burgundy and Franche-Comte in the east, politicians across the spectrum appealed to their supporters to go out and vote to head off a historic FN win.
Ahead of the vote, Valls had urged party activists to "appeal to patriotism" to ensure a massive turnout, with Le Pen accusing him of waging "total war" against her.
And the Republicans' deputy leader Nathalie Kosciusko-Morizet said it was time to "prove the polls wrong".
"Our duty is not to be paralysed by the polls and wait for the inevitable to happen, but to fight and fight until Sunday," she said.
The FN -- whose leaders have repeatedly linked immigration with terrorism -- has been climbing in the polls since the carnage in Paris.
When it emerged that at least two of the attackers had entered Europe posing as migrants, the FN went to town with message of "we told you so."
But any election triumph will depend on whether the other parties are able to forge alliances against it.
Socialist leaders will begin talks after the first results come in on Sunday to decide if they will withdraw from some second-round battles, with the Republicans meeting the following day to agree their strategy.
One Socialist expected to win is Defence Minister Jean-Yves Le Drian, a popular choice in the northwest Brittany region.