Left retains control in major cities like Paris, Lyon, and Marseille.
Alliances with La France Insoumise struggled against right-wing opposition.
Rassemblement National shows growing influence in mid-sized cities.
Briefing: French local elections expose left-wing infighting and RN's limits in big cities
Strategic angle: While the left managed to hold onto Paris, Lyon and Marseille, alliances forged with radical left La France Insoumise often failed against the right.