PARIS — President Emmanuel Macron of France was caught in a firestorm of criticism on Thursday after an aide from his office was identified in a video posing as a police officer and hitting a protester during a labor demonstration in May.

The man seen on the video was identified on Wednesday evening by the newspaper Le Monde as Alexandre Benalla, an aide to Mr. Macron’s deputy chief of staff who had been in charge of security during Mr. Macron’s 2017 presidential campaign.

On Friday, the office of Mr. Macron said that it would fire Mr. Benalla.

It was the latest in a string of recent controversies — including influence-peddling accusations against a close aide, a dust-up over an expensive new dinner service, and his scolding of a student — that have fed into accusations that Mr. Macron is a monarchical “president of the rich” who is out of touch with the French people.

Laurent Wauquiez, leader of the Republicans, a right-wing party, criticized the president on Europe 1 radio on Thursday morning. “When you are at the Élysée, you have to set an example,” he said, referring to the presidential palace. “And today, one has the feeling that at the Élysée, they think they are above the law.”