France began a frantically short election campaign on Monday, with President Emmanuel Macron's centrist alliance facing an uphill struggle to avoid another defeat at the hands of the far right.

Macron called the snap parliamentary polls three years early in a dramatic gamble to shake up French politics after the far right trounced his centrists in the EU elections. However, with less than two weeks before the vote, his alliance risks being squeezed by new coalitions forming on both the left and right.

Many in France remain baffled as to why Macron called an election just weeks before the country hosts the Olympics, risking the possibility of the far-right National Rally (RN) leading the government and 28-year-old Jordan Bardella becoming prime minister.

"Emmanuel Macron, who triggered this dissolution to trap the parties, has ended up trapping himself," said Le Monde daily, warning that the RN risked winning the election.

Candidates had until Sunday evening to register for the 577 seats in the lower house National Assembly ahead of the official start of campaigning at midnight.

The first round of voting will take place on June 30, followed by the decisive second round seven days later.

Earlier on Sunday, former French President Nicolas Sarkozy told Le Journal du Dimanche that Macron's decision to call snap elections could plunge France into "chaos, from which it will have the greatest difficulty emerging."

"Giving the floor to the French people' to justify the dissolution is a curious argument since this is precisely what more than 25 million French people have just done at the polls," Sarkozy said, referring to Macron's decision.

"The risk is great [that] they confirm their anger rather than reverse it," he added.