The far-right National Front (FN) party made unprecedented gains in the first round of regional French elections on Sunday.
French polling agencies show National Front won between 27 and 30 percent support nationwide, followed by former President Nicolas Sarkozy's center-right Republicans party and the governing Socialists.
The election comes as France remains under tight security following last month's terrorist attacks in Paris that left 130 people dead.
It is widely speculated that Marine Le Pen's anti-immigration, often Islamaphobic party would make political gains against the ruling Socialists.
French President Francois Hollande's personal approval ratings have soared with his hardline stance since the terrorist attacks, but his party's ratings remain low.
The FN's ratings have been rising since the Paris attacks. FN party leaders have consistently linked terrorism with immigration.
A second round of elections is scheduled for next Sunday.