Party leaders Olivier Faure, Manuel Bompard, Alexandre Loubet and Xavier Bertrand faced off on artificial intelligence policy on Friday in Marseille.
An internal audit criticizes the party's sociology and flags failures on violence and discrimination as members prepare to vote on a December referendum on running independently.
The former French prime minister spoke at the close of MoDem's back-to-school rally in Vaucluse, citing fears of a Le Pen-Mélenchon runoff.
The 'Un commun accord' assembly, made up of 150 randomly selected citizens, held its first session in Paris to shape debate on energy and climate issues.