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.