Table of Contents
The latest exclusive polls conducted by Cluster 17 in partnership with Politico paint a picture of a municipal campaign defined by narrow margins and potential surprises. Across several large French cities the left retains visible advantages, but those leads do not guarantee final victories. In this briefing we summarize the most significant snapshots released for different municipal contests and explain why the composition of second-round ballots could become decisive.
These polling releases arrived in stages: the Lille snapshot was published on Mar 10, Besançon on Mar 6, Nantes on Mar 5 and Marseille on Feb 26. Each survey focuses on intention-to-vote figures for the first round and models plausible second-round configurations. In the paragraphs that follow we outline city-specific numbers and then look at broader patterns: who is leading, which parties are underperforming, and which groups may act as kingmakers in runoffs.
Key national patterns
At the national level the polls highlight three recurring dynamics. First, the Socialist Party (PS) and allied left lists appear robust in many urban centers, often leading first-round tallies. Second, the performance of the Rassemblement National (RN) is mixed: it shows pockets of strength but does not uniformly convert into front-running positions. Third, smaller formations such as La France Insoumise (LFI) and the Ecologists are influential in shaping second-round arithmetic because they can either join left coalitions or stay independent. These trends mean that the initial leader after the first round may face a very different field at the runoff.
City-by-city snapshot
Lille and Besançon: narrow margins and strategic alliances
In Lille the incumbent mayor Arnaud Deslandes is reported as collecting the highest share of first-round intentions, giving the PS an apparent edge as of Mar 10. Yet pollsters note that the margin is not insurmountable: the rise of local alliances or an energized turnout could alter the picture. Besançon, with results dated Mar 6, looks even more volatile. The incumbent Ecologist mayor Anne Vignot and the main center-right contender Ludovic Fagaut are almost level. With both the RN and LFI hovering near the qualification threshold, the second round in Besançon could become a head-to-head duel, a three-way contest, or even a four-way race depending on who crosses the qualifying mark.
Nantes and Marseille: established names and surprising shifts
Nantes presents a classic city of left incumbency where the sitting PS mayor Johanna Rolland is polling at about 38% of intentions according to the Mar 5 release. Her lead is clear, but the center-right candidate Foulques Chombart de Lauwe at roughly 31% represents a stronger-than-expected push in a historically socialist stronghold. Marseille, where data was released on Feb 26, shows a fragmented field. The Republican candidate Vassal falls back to near 15%, while the contest for first place appears to be between the left-wing mayoral figure Benoît Payan and the right-populist contender Franck Allisio. That fragmentation increases the odds of complex second-round negotiations and tactical withdrawals.
What to watch for the second round
Three elements will determine final outcomes once the ballots move to the runoff. First, the ability of parties to form post-first-round alliances: collaboration between Ecologists, PS and LFI in some cities could consolidate a left majority, while unified center-right lists could reclaim ground elsewhere. Second, voter mobilization and abstention will be decisive; small shifts in turnout can flip margins in tight races. Third, the presence or absence of the RN in second-round ballots changes dynamics dramatically because its participation often leads to polarizing debates that reshape voter choices.
Conclusion and implications
These exclusive poll releases by Cluster 17 and Politico show the left retaining momentum in several major municipalities while underscoring how fragile many leads are ahead of any final runoffs. Cities such as Lille and Nantes display an advantage for sitting mayors, but Besançon and Marseille reveal how contested urban politics can become when multiple parties sit close to qualification thresholds. For observers and participants alike, the coming days will be about alliances, turnout and tactical decisions that will ultimately decide which first-round leaders convert advantage into victory.