France's far-right National Front (FN) saw record gains in the first round of regional polls, held under a state of emergency just three weeks after 130 people were killed in attacks in Paris.
Despite the strong result, FN faces an uphill battle to clinch a run-off vote next week after Socialists withdrew candidates to block it from power.
The FN came first with at least 30 percent of the vote nationwide and topped the list in at least six of 13 regions, according to estimates from the interior ministry.
The results are a new boost for Marine Le Pen's anti-immigration stance and a new blow to President François Hollande's Socialists. She and her 25-year-old niece Marion Marechal-Le Pen broke the symbolic 40 percent mark in their respective regions, shattering previous records for the party as they tapped into voter anger over a stagnant economy and security fears linked to Europe's refugee crisis.
Marine Le Pen, a lawyer by training, welcomed the "magnificent result," saying it proved the FN was "without contest the first party of France."
A grouping of right-wing parties took 27 percent, the official estimates showed, while the ruling Socialist Party and its allies took 23.5 percent.
Polling agency projections suggested the far right National Front took the lead in the first round of France's regional elections on Sunday.
The agencies Ifop, OpinionWay and Ipsos based their projections on the actual vote count in select constituencies. They projected that the National Front won between 27 and 30 percent support nationwide, followed by former President Nicolas Sarkozy's Republicans party and the governing Socialists.
The elections Sunday took place in an unusually tense security climate just over three weeks after deadly attacks on Paris, a climate expected to favor conservative and far right candidates.
The Paris attacks on Nov. 13 inspired by the Islamic State in Iraq and the Levant (ISIL) and a Europe-wide refugee crisis this year has shaken up France's political landscape.
Hollande has seen his approval ratings jump since the Paris attacks, as he intensified French airstrikes on ISIL targets in Syria and Iraq, and ordered a state of emergency at home. But his party, which currently runs nearly all of France's regions, has seen its electoral support shrivel as the government has failed to reduce a 10 percent joblessness rate or to invigorate the economy.
"There will be a 'punishment vote' for sure" against the Socialist government, said Parisian voter Daniel Vernet.
Voters are choosing leadership for the country's 13 newly-redrawn regions in elections that start Sunday and go to a second round Dec. 13.
The regional vote has taken on greater meaning in the wake of the Paris attacks. Many political leaders are urging apathetic voters to cast ballots as a riposte to fighters targeting democracies from France to the United States.
However, turnout was just over 16 percent at midday, barely higher than during regional elections five years ago.
First-time voter Eli Hodara, an 18-year-old Paris student, expressed hope that more young people would turn out. "I think it is important to vote even if one leaves the ballot blank."
It is the last election before France votes for president in 2017, and a gauge of the country's political direction.
"It's an important moment, important for the future of our regions, important also for the future of our country, important with regard to the catastrophic and dramatic events that have hit France," Le Pen said as she cast her ballot in the northern city of Henin-Beaumont.
Socialist Prime Minister Manuel Valls and the conservative-leaning national business lobby issued a public appeal this week to stop the National Front's march toward victory. Le Pen has worked to undo its image under her father and co-founder, Jean-Marie Le Pen as an anti-Semitic party and has lured new followers from the left, the traditional right and among young people.
The arrival of hundreds of thousands of migrants in Europe and the exploits of ISIL, which has claimed responsibility for the Paris attacks, have bolstered the discourse of the National Front. It denounces Europe's open borders, what it calls the "migratory submersion" and what it claims is the corrupting influence of Islam on French civilization.
Al Jazeera and The Associated Press