"On the evening of the first round and no doubt on the evening of the second round when the final results are announced, the ultra-left and ultra-right can take advantage of this to sow a form of chaos," the minister told broadcaster France Info.
He responded to questions posed by the broadcaster based on a 10-page memo it obtained that his ministry distributed to police prefects.
In the document, Darmanin highlighted a "context shaped by several security risks" and the concern over "targeted destabilisation actions".
A National Rally election win could make Jordan Bardella the new French prime minister. (AP PHOTO)
France's parliamentary elections are being held in two rounds on Sunday and on July 7.
French President Emmanuel Macron called snap National Assembly elections earlier this month in response to the defeat of his centrist forces in the European elections and a resounding victory for the populist conservative National Rally.
In the France Info interview, Darmanin also warned of "extremely serious unrest" after the political summer break from September onwards, should the far right or far left come to power.
If one of the two camps begins to implement its economic plans, France could face pressures on the financial markets, he said.
The autumn is traditionally a period when unions in France organise rallies to voice social demands or protest government plans, adding another layer of potential tension.
Polls indicate that the anti-immigration National Rally could greatly increase its number of MPs in the National Assembly.
A National Rally victory risks saddling the president with Jordan Bardella as prime minister.
Bardella, a 28-year-old protege of National Rally leader Marine Le Pen and with no governing experience, says he would use the powers of prime minister to stop Macron from continuing to supply long-range weapons to Ukraine for the war with Russia.
He cites fears that their ability to strike targets in Russia could suck nuclear-armed France into direct confrontation with the nuclear-armed government in Russia.
But France's two-round system of voting - the initial balloting on Sunday will thin the field for decisive follow-up voting on July 7 - means the election's ultimate outcome is very uncertain.
with AP
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