The popularity of the outspoken candidate is beginning to wane, according to the latest polls.
Mr Zemmour, a newspaper polemicist and TV pundit, has seen his ratings soar in recent months and weeks on the back of his anti-Islam and anti-immigrant rhetoric.
However, now support for this candidate appears to be faltering.
His advisors have admitted he is at a crossroads and in need of a boost if he is going to beat out the other far-right contender Marine Le Pen to the second round of the April election.
Olivier Ubéda, his press officer, said the gesture had been a gut reaction after the visit to Marseille was interrupted by far-left protesters.
Mr Ubéda said: “Éric Zemmour does not deny it. It’s instinctive. You’ll have to get used to it with him.”