[3][4] During the 2005 French referendum campaign on the European Constitution he gained public attention by advocating against it,[5][6] notably for his discussion with Dominique Strauss-Kahn.

[13] This increasing popularity led to a re-examination of his long advocacy for direct democracy, and also of positive statements he had made about several right-wing conspiracy theorists, such as Alain Soral, Antony Sutton, Jacques Cheminade, Eustace Mullins, or Thierry Meyssan, and the relationship he has maintained with them.

[15] In April 2019, he declared on Sud Radio, in a debate with Elisabeth Lévy: “You find that the freedom not to love a religion is very important.

[17][18] Asked in June 2019 on Le Média about the existence of the gas chambers during the Second World War, he replied that "it's not [his] subject", that he "knows nothing about it" and has “never read anything about it”.

[23] Faced with the controversy, he said he "regrets" his remarks, admits having "said a huge bullshit", affirming "not to be a Holocaust denier, and not to be anti-Semitic", and ensuring that "the gas chambers are an absolute horror".