Mr. Benalla was suspended for 15 days without pay and was told that he was no longer in charge of organizing security during presidential trips, Mr. Roger-Petit said, adding that the disciplinary sanctions were presented to Mr. Benalla “as a last warning before firing.”
But Mr. Macron’s opponents called the sanctions too lenient and asked why the presidency had not referred the case to prosecutors, noting that the French penal code makes it mandatory for public officials to do so if they become aware of a crime.
Jean-Luc Mélenchon, the leader of the leftist party France Unbowed, said it was an “exceptionally serious affair” and that the presidency needed to clarify who was responsible for letting Mr. Benalla attend the demonstration.
It was unclear on Thursday how closely Mr. Benalla worked with Mr. Macron on a day-to-day basis, but the aide is seen alongside the president in pictures of several public events, and Le Monde reported that Mr. Macron’s chief of staff told him about Mr. Benalla’s actions on May 1.
“If we accept that anybody can act like a police officer alongside the police, then we are no longer under the rule of law,” Mr. Mélenchon told reporters at the National Assembly, France’s lower house of Parliament.
Mr. Roger-Petit, the spokesman, also confirmed on Thursday that a second man who had worked for the president’s office had been sanctioned for actions on May 1, although it was not immediately clear if he was also in the video showing Mr. Benalla.
The man, a reservist gendarme named Vincent Crase, was also an employee of Mr. Macron’s political party, La République en Marche, according to Mr. Roger-Petit, who said Mr. Crase was “occasionally mobilized, like other reservists” to help with the president’s security. Mr. Crase also received a 15-day suspension without pay, and the presidency has stopped working with him, Mr. Roger-Petit said.
Reports in the French news media said that despite the sanctions, Mr. Benalla continued to work occasionally on security outside the presidential palace, including during the burial of Simone Veil at the Panthéon and for the return from the World Cup of the victorious French soccer team, with footage showing him next to the team bus.