PARIS  — A coalition on the left that came together unexpectedly ahead of France’s snap elections won the most parliamentary seats in the vote, according to polling projections Sunday. The surprise projections put President Macron’s centrist alliance in second and the right wing in third.

The lack of majority for any single alliance plunged France into political and economic turmoil. Final results are not expected until late Sunday or early Monday in the highly volatile snap election, which was called just four weeks ago in a huge gamble for Mr. Macron.

The deeply unpopular president lost control of parliament, according to the projections. Marine Le Pen’s National Rally drastically increased the number of seats it holds in parliament but fell far short of expectations.

The snap legislative elections in this nuclear-armed nation and major economy will influence the war in Ukraine, global diplomacy and Europe’s economic stability.

France now faces the prospect of weeks of political machinations to determine who will be prime minister and lead the National Assembly. And Mr. Macron faces the prospect of leading the country alongside a prime minister opposed to most of his domestic policies.

French leftist leader Jean-Luc Mélenchon called the projections an “immense relief for a majority of people in our country” and he demanded the resignation of the prime minister. Mélenchon is the most prominent of the leftist leaders who unexpectedly came together ahead of the two-round elections.

The projections, if confirmed by official counts expected later Sunday or early Monday, plunge a pillar of the European Union and its second-largest economy into intense uncertainty, with no clarity about who might partner with President Emmanuel Macron as prime minister in governing France.

The timing of France’s leap into the political unknown could hardly be worse: With the Paris Olympics opening in less than three weeks, the country will be grappling with domestic instability when the eyes of the world are upon it.

For 46-year-old Mr. Macron’s centrists, the legislative elections have turned into a fiasco. He stunned France, and many in his own government, by dissolving parliament’s lower house, the National Assembly, after the far right surged in French voting for the European elections.

Mr. Macron argued that sending voters back to the ballot boxes would provide France with “clarification.” The president was gambling that with France’s fate in their hands, voters might shift from the far right and left and return to mainstream parties closer to the center — where Mr. Macron found much of the support that won him the presidency in 2017 and again in 2022. That, he hoped, would fortify his presidency for his remaining three years in office.

But rather than rally behind Mr. Macron, millions of voters on both the left and right of France’s increasingly polarized political landscape seized on his surprise decision as an opportunity to vent their anger and possibly sideline Mr. Macron by saddling him with a parliament that could now largely be filled with lawmakers hostile both to him and, in particular, his pro-business policies.

Already in last weekend’s first round of balloting, voters massively backed candidates from the far-right National Rally, in even greater numbers than in voting for the European Parliament. A coalition of parties on the left took second and his centrist alliance was a distant third.

A hung parliament with no single bloc coming close to getting the 289 seats needed for an absolute majority in the National Assembly, the more powerful of France’s two legislative chambers, would be unknown territory for modern France and usher in political turmoil.

The Associated Press