Greens candidate Jean-Laurent Felizia has withdrawn from a second round run-off vote in the southeastern region of Provence-Alpes-Cote d'Azur (PACA), clearing the way for a duel between the centre-right and the far-right - making it harder for Marine Le Pen's party to win its first ever region.
But after Felizia's withdrawal, if left-leaning voters now transfer their second round ballot to Renaud Muselier, the candidate for the conservative Républicains who came second in round one, the region will remain under the control of the mainstream right.
French mainstream parties have traditionally rallied behind the one best placed to keep the far right out of power in local and national elections, a strategy known as "front republicain".
The ecologist candidate Felizia, who garnered 16.89 percent of the vote, initially rebuffed calls to stand down in order to block the National Rally but then bowed to pressure from others on the allied leftist list, which included fellow Green, Socialist and Communist Party candidates.
"It would be wrong to play with fire," Felizia told a press conference, announcing that he would pull out and would himself vote in the second round for incumbent Renaud Muselier.
Meanwhile in the Ile-de-France region, which includes Paris, the leftist candidates joined forces to try to beat Valérie Pécresse of Les Républicains, who easily won in round one with 35.94 percent of the vote.
The election was marked especially by a record-low turnout, leading Prime Minister Jean Castex to issue a "solemn appeal" to the French on Monday morning to exercise their right to vote, amid dismay across the political spectrum.