French far-right National Front leader Marine Le Pen casts her ballot during regional elections in the Nord Picardie region, on December 6, 2015
Paris (AFP) - France's far-right National Front was tipped for historic gains as regional polls were held Sunday under a state of emergency just three weeks after Islamic extremists killed 130 people in Paris.
Around 45 million people are eligible to vote in an election being held under 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.
The last opinion poll on Friday by Ipsos-Sopra said the FN would take the largest slice of the vote -- 29.5 percent -- followed by a mix of right-wing and centrist parties on 28.5 percent and the ruling Socialists on 23 percent.
FN leader Marine Le Pen was on course to win control of the economically depressed northern region of Nord-Pas-de-Calais-Picardie, once a bastion of the left.
Her 25-year-old niece Marion Marechal-Le Pen seemed 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" next Sunday, Marine Le Pen said as she cast her vote.
First projections were expected at 1900 GMT.
France's regions have recently been consolidated and given more power over areas such as schools, transport and support for local businesses.
- Hollande's Socialists languish -
Casting his ballot in Evry south of Paris, Prime Minister Manuel Valls said: "I hope many French people will vote, especially after the terrorist attacks. We shall overcome, and our weapon is our vote."
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 seen as in with a chance in the eastern Alsace-Champagne-Ardennes-Lorraine region that borders Belgium and Germany, according to polls by Ipsos and Odoxa.
If traditional parties refuse to join forces against them, analysts predict the FN could take all three regions on December 13, when voters return to the polls to pick from the top two parties of the first round.
- 'We told you so' -
Victory would not only put the party at the head of a regional government for the first time, but would also give Le Pen a springboard for her presidential bid in 2017.
In her campaign, she has focused repeatedly on the migrant camp in Calais known as "The Jungle" where thousands of people are camped 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 head off a historic victory by the party.
Ahead of the vote, Valls urged party activists to "appeal to patriotism" to ensure a massive turnout, with Le Pen accusing him of waging "total war" against her.
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 a 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 whether to withdraw from some second-round battles, while the Republicans' strategy meeting is set for Monday.
One Socialist expected to win is Defence Minister Jean-Yves Le Drian, a popular choice in the northwestern Brittany region.