French Prime Minister Gabriel Attal said he would submit his resignation on Monday, after early poll data showed his and French President Emmanuel Macron's centrist Ensemble party and its allies coming in second in the parliamentary runoff.

Ensemble and its allies are projected to secure between 150 and 180 seats, according to an IFOP estimate, behind the leading New Popular Front's 180-215 result.

Both factions have outpaced the winner of the first parliamentary vote, the far-right Rassemblement National — RN or National Rally.

France now looks likely to be stranded in a hung-parliament scenario that divides it between three strongly represented parties that must broker alliances to gain absolute control.

Attal, who stepped in as France's youngest ever prime minister only in January, is unlikely to hold the country's second-highest position as part of the upcoming administration.

"Faithful to the Republican tradition and in accordance with my principles, tomorrow morning I will submit my resignation to the president of the Republic," Attal said Sunday, according to a CNBC translation.

"I know that, in light of the results of this evening, many French people feel a certain uncertainty about the future, as no absolute majority has emerged [in parliament]. Our country is experiencing an unprecedented political situation," Attal added

His departure was widely expected in the wake of the first presidential vote, when analysts had circulated the possibility that Macron would have to concede the prime minister's office to RN leader Jordan Bardella, if the far right retained its advance.

"From the beginning of this campaign, I was alerted to three risks: the risk of an absolute majority dominated by the France Unbowed, the risk of an absolute majority dominated by Rassemblement National, and the risk of the disappearance of a movement that embodies our ideas and our values," Attal said Sunday night. "These three risks, today, were discarded by the French people. Tonight, no absolute majority can be led by the extremes."

In light of the run-off results, Attal set the scene for a period of transition for France's political landscape:

"Ladies and gentlemen, this evening, a new era begins. A new era for our nation," he said.

Faced with uncertainty in one of Europe's forefront economies, markets will be following the next few days for indications of what alliances will forge to achieve ruling majority.

France's leadership is unlikely to be entirely dismantled in the wake of the elections, as Macron has previously indicated he would serve out the remainder of his term until 2027, irrespective of the outcome of the vote.