Former French Economy Minister Arnaud Montebourg (C) arrives to deliver a speech during the 44th annual meeting of the French socialist party (PS) "La fete de la Rose", on August 21, 2016 in Frangy-en-Bresse. Arnaud Montebourg announced his candidacy for the 2017 presidential elections, on August 21, 2016 in Frangy-en-Bresse (Saône-et-Loire). He also said that his presidential project will be "socialist but not only" and that was impossible for him to support French President France Hollande. / AFP PHOTO / PHILIPPE DESMAZESPHILIPPE DESMAZES/AFP/Getty Images

Former French Economy Minister Arnaud Montebourg (R) greets supporters prior to deliver a speech during the 44th annual meeting of the French socialist party (PS) "La fete de la Rose", on August 21, 2016 in Frangy-en-Bresse. Arnaud Montebourg announced his candidacy for the 2017 presidential elections, on August 21, 2016 in Frangy-en-Bresse (Saône-et-Loire). He also said that his presidential project will be "socialist but not only" and that was impossible for him to support French President France Hollande. / AFP PHOTO / PHILIPPE DESMAZESPHILIPPE DESMAZES/AFP/Getty Images

Former French Economy Minister Arnaud Montebourg (C) greets supporters prior to deliver a speech during the 44th annual meeting of the French socialist party (PS) "La fete de la Rose", on August 21, 2016 in Frangy-en-Bresse. Arnaud Montebourg announced his candidacy for the 2017 presidential elections, on August 21, 2016 in Frangy-en-Bresse (Saône-et-Loire). He also said that his presidential project will be "socialist but not only" and that was impossible for him to support French President France Hollande. / AFP PHOTO / PHILIPPE DESMAZESPHILIPPE DESMAZES/AFP/Getty Images

Former French Economy Minister Arnaud Montebourg (C), flanked by former French Culture Minister Aurelie Filippetti (2nd L) waits prior to deliver a speech during the 44th annual meeting of the French socialist party (PS) "La fete de la Rose", on August 21, 2016 in Frangy-en-Bresse. Arnaud Montebourg announced his candidacy for the 2017 presidential elections, on August 21, 2016 in Frangy-en-Bresse (Saône-et-Loire). He also said that his presidential project will be "socialist but not only" and that was impossible for him to support French President France Hollande. / AFP PHOTO / PHILIPPE DESMAZESPHILIPPE DESMAZES/AFP/Getty Images

Former French Economy Minister Arnaud Montebourg (R) shakes hands with supporters prior to deliver a speech during the 44th annual meeting of the French socialist party (PS) "La fete de la Rose", on August 21, 2016 in Frangy-en-Bresse. Arnaud Montebourg announced his candidacy for the 2017 presidential elections, on August 21, 2016 in Frangy-en-Bresse (Saône-et-Loire). He also said that his presidential project will be "socialist but not only" and that was impossible for him to support French President France Hollande. / AFP PHOTO / PHILIPPE DESMAZESPHILIPPE DESMAZES/AFP/Getty Images

Former French Economy Minister Arnaud Montebourg (C), flanked by former French Culture Minister Aurelie Filippetti (R) arrives to deliver a speech during the 44th annual meeting of the French socialist party (PS) "La fete de la Rose", on August 21, 2016 in Frangy-en-Bresse. Arnaud Montebourg announced his candidacy for the 2017 presidential elections, on August 21, 2016 in Frangy-en-Bresse (Saône-et-Loire). He also said that his presidential project will be "socialist but not only" and that was impossible for him to support French President France Hollande. / AFP PHOTO / PHILIPPE DESMAZESPHILIPPE DESMAZES/AFP/Getty Images

Former French Economy Minister Arnaud Montebourg gestures as he delivers a speech during the 44th annual meeting of the French socialist party (PS) "La fete de la Rose", on August 21, 2016 in Frangy-en-Bresse. Arnaud Montebourg announced his candidacy for the 2017 presidential elections, on August 21, 2016 in Frangy-en-Bresse (Saône-et-Loire). He also said that his presidential project will be "socialist but not only" and that was impossible for him to support French President France Hollande. / AFP PHOTO / PHILIPPE DESMAZESPHILIPPE DESMAZES/AFP/Getty Images

Former French Economy Minister Arnaud Montebourg gestures as he delivers a speech during the 44th annual meeting of the French socialist party (PS) "La fete de la Rose", on August 21, 2016 in Frangy-en-Bresse. Arnaud Montebourg announced his candidacy for the 2017 presidential elections, on August 21, 2016 in Frangy-en-Bresse (Saône-et-Loire). He also said that his presidential project will be "socialist but not only" and that was impossible for him to support French President France Hollande. / AFP PHOTO / PHILIPPE DESMAZESPHILIPPE DESMAZES/AFP/Getty Images