The French centrist faced the biggest political crisis of his tenure after a video of his security chief beating up two protesters was revealed by the daily Le Monde last month.
The poll, conducted by YouGov for the Huffington Post and the French television channel CNews, showed that Mr Macron’s approval rating had fallen to 27 per cent, down five percentage points from June.
The survey also marked the young centrist’s lowest YouGov approval rating since he took power in May 2017.
At 62 per cent, Mr Macron’s disapproval rating reached a record high, YouGov said, although the polling institute stressed that respondents had been asked to comment on “the president’s actions, and not on his image”.
Mr Macron’s office came under fire last month after Alexandre Benalla, the former head of the president’s security detail, was caught on camera assaulting two May Day protesters while off duty and wearing a riot helmet and police tags.
The video, which was released by the left-leaning daily Le Monde on July 18, sparked nationwide outrage, with opposition leaders accusing the government of failing to properly punish Mr Benalla or refer him promptly to judicial authorities.
Mr Macron faced further criticism after he slammed the French media’s coverage of the incident.
He said: “We have a press that is no longer pursuing the truth… What I see is media power that wants to become judicial power.”
Mr Benalla, 26, was sacked shortly after the video was made public and charged with gang violence and impersonating a police officer.
However, another poll also published last week painted a more positive picture of Mr Macron’s presidency in the wake of the Benalla scandal.
The survey, conducted by Elabe for the newspaper Les Echos and Radio Classique, found that Mr Macron’s popularity rating had climbed two percentage points in one month, with 36 per cent of respondents saying they trusted him to fix the country’s problems.
Sixty per cent of those polled said they “didn’t trust” him.
Eight out of 10 people, however, said they were “shocked” by Mr Benalla’s behaviour.
Several French pollsters have since weighed in on Mr Macron’s mixed bag poll results.
Ifop’s deputy chief Frédéric Dabi said that the scandal had had a “real impact” but failed to dent public opinion; while Jean-Daniel Lévy of Harris Interactive likened the controversy to a “slow poison” that could come back to haunt the Mr Macron in the future.
The YouGov poll of 1,017 people was carried out online between July 25 and July 26; while the Elabe poll of 1,007 people was carried out online between July 31 and August 1.