French President Emmanuel Macron has been heavily criticized for warning that a far-right or hard-left victory in the snap elections could trigger a "civil war".
His opponents urged him not to scare the public, AFP reported.
France is preparing to vote on June 30 in the country's most polarizing vote in decades. Macron called the parliamentary elections after the far-right National Rally party scored a landslide victory in European Parliament elections earlier this month.
The election is shaping up as a clash between the far-right National Front and the leftist New Popular Front, which is dominated by the hardline France Unbowed party.
Macron has warned that the agendas of the two "extremes" could trigger a "civil war", accusing both the NR and France Unbowed of sowing tension and dividing people.
Leaders of both the left and the right condemned his remarks.
Eric Coetzee, the leader of the conservative Republicans, who sparked outrage among his allies by personally agreeing to a pre-election pact with the NR, accused the French president of irresponsibility.
"This is a strategy of fear," he said.
CNP heavyweight Marine Le Pen said Macron's argument was "weak" and showed "he thinks he has lost this election".
Patrick Canet, head of the Socialist group in the Senate, said Macron's statement showed he was fighting for his political survival.
"We are facing a man who no longer controls anything," he said.
Jean-Luc Melenchon, head of France Unbowed, also criticized Macron: "He is always there to set things on fire."
The three main camps - left, far-right and centrist - will hold a key televised debate tonight.
It will pit Prime Minister Gabriel Atal of Macron's centrist Renaissance party against the leader of the far-right NR Bardella party and Manuel Bompard of the left-wing New Popular Front.
According to some polls, the NR could win 35-36% in the first round of voting, ahead of the left-wing Alliance with 27-29.5%, with Macron's centrists in third with 19.5-22%.
A second round of voting will follow on 7 July in constituencies where no candidate took more than 50% in the first round. | BGNES
