The French Resistance planned acts of sabotage on telecommunication networks.
The French intelligence service, the Deuxime Bureau stayed loyal to the Allied cause despite nominally being under the authority of Vichy; the Deuxime Bureau continued to collect intelligence on Germany, maintained links with British and Polish intelligence and kept the secret that before World War II Polish intelligence had devised a method via a mechanical computer known as the Bombe to break the Enigma machine that was used to code German radio messages
 Two Frenchmen serving in the SOE, Raymond Basset (codename Mary) and Andr Jarrot (codename Goujean), were parachuted in and were able to repeatedly sabotage the local power grid to sharply lower production at the Schneider-Creusot works

