France's far-right National Front topped the vote nationally in the first round of high-stakes regional elections on Sunday, according to exit polls.
Boosted by fears over the 13 November Islamic State attacks that killed 130 people in Paris, stubbornly high unemployment and worries about immigration, Marine Le Pen's party secured 30.6 percent of the vote nationally, an exit poll by Ifop-Fiducial showed.
The anti-Europe, anti-immigration party beat former president Nicolas Sarkozy's conservative Les Republicains party and their allies, who secured 27 percent, into second place. As expected, President Francois Hollande's ruling Socialists came third, polling 22.7 percent.
A second round of voting takes place on 13 December.
The National Front (FN) has not won any region outright in the first round but, if the result is confirmed, it would be well placed to do well in the run off in a week's time.
It has so far never ruled in anything bigger than less than a dozen French towns.
Ms Le Pen herself came first in the north and her niece Marion Marechal-Le Pen in the southeast, each gaining more than 40 percent of the votes in those two regions.
The FN has come first in six regions out of twelve, another poll for France 2 television showed, with the result for the thirteenth region, Paris, not yet known.
Winning even one regional constituency would be a major boost for Ms Le Pen, who wants to use a base of locally elected officials to target the top levels of power. Her eye is on the 2017 presidential and general elections.
The key question will now be whether the Socialists, seen third behind the FN and the Republicans in regions which the far-right could win over on 13 December, will pull out of the race in those regions to try to keep them out of power.
The Socialist party's top officials were meeting on Sunday night but might make their decision known only on Monday.
French regions rule over local transport and economic development as well as high schools and vocational training, with beefed-up powers after a reform that cut their numbers from 22 to 13.