Un Plan de Sauvegarde
Though his doctors had repeatedly begged him to be better about staying up on his checkups, Francois Mitterrand found himself a man with little time for things like regular health checkups or cancer screenings, despite his long history of health issues throughout the 1970s. Having defeated the ostensibly more popular Michel Rocard of the right wing of the
Parti Socialiste at the 1979 Metz Congress, he had spent much of the intervening winter trying to update the
Common Programme ahead of his anticipated rematch with Valery Giscard d'Estaing in the spring elections of 1981 and continue to position the PS ahead of the Communists as the genuine standard-bearer of the French left. As spring progressed, though, Mitterrand continued feeling more and more fatigued, less able to maintain his daily routines, and his friends and colleagues began commenting that he was losing weight and frequently looked pale. Finally, in late April, he collapsed while speaking to a trade union of Renault machinists near Paris and was rushed to the hospital. Doctors confirmed what many Socialists quietly suspected - Mitterrand's cancer had returned with a vengeance.
[1] Treatments were begun and Mitterrand dramatically drew down his scheduling commitments, but the aggressive disease had already spread too far. After suffering a fall late in evening of June 5, 1980, Francois Mitterrand died at the Hôtel-Dieu early the next morning. He was 63 years old.
Mitterrand had been a towering figure of the past thirty years of French politics and with the exception of Guy Mollet easily the most dominant personality on the French left. France's economic struggles in the late 1970s depression had convinced many that the "quiet force" of Mitterrand presented the opening for a leftist head of state for the first time since the Third Republic and an end to the Gaullist hegemony that Mitterrand had spent his career so bitterly fighting. The immediate beneficiary of his death, of course, was not even President Giscard d'Estaing, who was arguably slightly favored in the following year's election based on Fifth Republic political history, but Rocard, who had thought himself the likely champion of the French Left already and now seemed to clearly have a Presidential nomination within reach. The issue for Rocard, of course, was that Mitterrand's star burning out could easily lead to a resurgence of the PCF and the cementing of the Gaullists thanks to a public skepticism of Communism (to say nothing of American and British pressure, even from center-left governments). But first, of course, was Mitterrand's funeral, which most notable French political figures attended (and which his wife and mistress attended together as well)
[2], and then the knives could come out later...
[1] So, this is based on a suggestion from way back in this TL of how to kill off Mitterrand ahead of 1981. Apparently, his cancer did come back sometime in 1979/80 and nearly killed him; here, Mitterrand merely doesn't stay on top of his screenings like he should and off he goes.
[2] Gotta keep the best Mitterrand anecdote, even if sixteen years early