Socialists and allies held on to power in France's big four cities - Paris, Marseille, Lyon, and Lille - during a local election night that sparked optimism for mainstream parties ahead of the upcoming presidential elections.

New aspirants from the far-left and far-right also made gains, particularly in Nice with an ally of Marine Le Pen and Roubaix in the north for the France Unbowed (LFI) party.

However, the significant lesson from the evening was the failure of alliances between mainstream left factions and the LFI, with voters shifting towards center-right options in traditional Socialist strongholds such as Clermont-Ferrand and Brest.

In contrast, cities like Paris, Marseille, and Lille – where incumbent Socialists distanced themselves from the far-left due to accusations of anti-Semitism within its ranks – saw left-wing administrations comfortably returned.

Lyon was a notable exception, where ecologist mayor Gregory Doucet allied with LFI and achieved victory, against a backdrop of a weak campaign from right-wing challenger Jean-Michel Aulas.

Despite the evening's failures for left-far-left coalitions in Toulouse, Strasbourg, Poitiers, Limoges, and Tulle, the LFI’s Manuel Bompard highlighted victories in the northern Paris suburb of Saint-Denis and Roubaix, suggesting the party remains a player in some regions.

Grégoire's win in Paris aligned with polling forecasts, maintaining the city’s left-wing identity, buoyed by his predecessor Anne Hidalgo's popular anti-car policies. Rachida Dati, the right-wing challenger, faced challenges due to her controversial past and association with figures from the far-right.

Overall, while the far-right National Rally (RN) showcased strength in provincial towns, mainstream parties of the left, right, and center emerged as the primary victors in this electoral round, leaving them with renewed reasons to believe in their appeal against extremist candidates in future elections.

The outcomes re-emphasize the challenges for the traditional left and raise important questions about the electoral landscape as France heads towards the 2027 presidential election.