Castex said the 18,181 new cases recorded in the 24 hours to Tuesday afternoon represented a 140% jump on the previous week and claimed that 96% of these new infections were observed in unvaccinated people.
"We are in the fourth wave," Castex told TF1 news. "The infamous Delta variant is here, it is here, it is the majority (of cases) and what characterises it from those that preceded it is that it is much more contagious.
"We must react and at the same time, the key is known, it is not completely new but the contagiousness of this Delta variant obliges us even more, we must vaccinate," he said.
His television address comes as the COVID-19 health pass — attesting the holder has either been fully vaccinated, tested negative over the previous 48 hours or recovered from the disease over the previous six months — is being made mandatory to visit leisure and cultural venues.
A bill planning for the health pass requirement to be extended to bars, restaurants, shopping centres and long-distance public transport from early August is currently being debated by French MPs.