According to Christophe Bourseiller, during Guionnet's youth, he led a far-left group called Oser lutter, oser vaincre ("Dare to struggle, dare to beat"), based in Issy-les-Moulineaux [REF].
In 1988, he took an interest in former commandant of Bergen-Belsen concentration camp Josef Kramer's trial through a book [REF].