Did several French firefighters turn their back towards President Macron during a ceremony and did they then walk out on him, unfurling a banner which read "Moins de pompiers, secours en danger" (fewer firefighters, safety in danger)? No, that's not true: the video is real but it does not show Macron.
The claim appeared in a tweet published on December 3, 2018 by someone named "Cossack" on Twitter (archived here, video archived here) which read:
"When this happens you know you are done. FireFighters turn their backs and walk out on Macron. The end is near. https://t.co/ifdij0TJSN"
When this happens you know you are done.
-- Cossack (@Victor_Drezna) 3 december 2018
FireFighters turn their backs and walk out on Macron. The end is near.pic.twitter.com/ifdij0TJSN
According to local media reports the firemen did indeed turn their backs during a ceremony on December 2, 2018 in Cholet for the feast of Saint Barbara (patron saint of firemen and others in jobs involving fire and explosions):
Cholet: les pompiers tournent le dos aux élus lors d'une célébration (vidéo)
C'est une image forte qu'ont imposé les pompiers de Cholet samedi 1er lors des célébrations de la Sainte-Barbe, la sainte patronne des soldats du feu. Pour protester contre les réductions des moyens qui leur sont alloués, les pompiers ont décidé, dès le début de la cérémonie, de se retourner et de présenter leur dos aux élus présents, comme le rapporte Ouest-France.
Macron was not present during the ceremony. The man in the sash is Denis Masséglia, a member of the French parliament (Assemblée nationale) elected for Macron's party "La République En Marche!" (LREM).
From the slogan on the banner unfurled by the firemen it appears they are protesting budget cuts, not the government or president in general.