This fall, France’s former president Nicolas Sarkozy was briefly imprisoned in a criminal case involving alleged corruption and illegal campaign financing by Muammar Gaddafi. Sarkozy’s three weeks in a Paris jail were a major political event — the first instance of a French head of state being imprisoned since the collaborationist Marshal Philippe Pétain’s conviction after World War II.

Now Sarkozy has written a book about the experience. He used the moment not just to talk about prison life but to declare an end to the cordon sanitaire that has informally proscribed mainstream parties from allying with Marine Le Pen’s Rassemblement National (RN). If conservatives long pledged opposition to this party’s fascist heritage and politics, they are now weakening this stance.

“When the time comes, I’ll take a public position on the subject,” Sarkozy writes in Le journal d’un prisonnier (Prisoner’s Journal), calling for an end to the “artificial” cordon and emphasizing that the RN is not a danger to the Republic.