Raphaël Glucksmann holds the strongest position among declared contenders for the first round of the October 9-10 primary, which will select the social-democratic candidate for the 2027 presidential election through an electronic vote open to PS and Place Publique members plus paying sympathizers. His lead stems from consistent polling strength for the general election, his European Parliament profile, and the July militant decision to limit the electorate to the narrower "pôle socialiste" rather than a broader left contest. Olivier Faure, Jérôme Guedj, Philippe Brun, Ségolène Royal, and Emmanuel Maurel remain active challengers, with recent exchanges highlighting divisions over the 15-euro voting fee and Faure's push to widen participation to figures such as François Ruffin. Glucksmann has rejected rule changes ahead of the September 15 candidate deadline, reinforcing trader assessments that his organized base and refusal to dilute the contest give him the clearest path to a first-round plurality.