As of July 1940, the wounded Guingouin returned to his homeland, the Limousin, and became involved with local resistance groups . This initially took the form of membership of clandestine groups, who published and dispersed leaflets against the Vichy government but then moved on to the production of false identity cards. Nevertheless, Guingouin's ideology soon put him at odds with the political agenda advocated by Jacques Duclos, the then underground leader of the Communist Party.

Pre-empting the Communist Party's declaration of September 1940 which stated: "we (the Communists) must be without hatred toward and must have respect for the German soldiers. We are against Gaulle and the capitalist clan whose interests are related to Vichy", Guingouin led the call to the fight against the Nazis in August 1940 with his "Appel à la lutte", typed by the Parisian typist Madame Lepage, who as a "sympathisante" had taken refuge in Saint-Gilles-les-Forets.

Although Guingouin was a communist, he claimed to be able to work, albeit loosely, with and not against General de Gaulle and the other resistance groups operating throughout France at the time, most of whom were aligned to De Gaulle's nationalistic cause. On the other hand, the approach of Duclos, the then leader of the the French Communist Party, was based on the terms of The Nazi-Soviet Non-Aggression Pact, signed by August 14, 1939.

German Foreign Minister Joachim von Ribbentrop had contacted the Soviets to arrange a deal whereby Ribbentrop met with the Soviet Foreign Minister Vyacheslav Molotov in Moscow and together they arranged two pacts - the economic agreement and the Nazi-Soviet Non-Aggression Pact.

As a result of the Nazi-Soviet Non-Aggression Pact, the Soviets did not join the fight against Germany, thus Germany was successful it its attempt to safeguard itself from a two-front war. The Nazis and the Soviets kept the terms of the pact and the protocol until Germany's surprise attack and invasion of the Soviet Union on June 22, 1941.

Guingouin's split with the Party line eventually led him to "take the maquis" in February I941 under the clandestine name of "Raoul". The Police had become aware of Guingouin's work and raided his home. As a consequence he was forced to flee and take refuge in, amongst other places, a fir plantation in the commune of Soudaine-Lavinadière in Corrèze. During this time, Guingouin was frequently ill due to the wounds he had sustained and the life he was forced to lead nevertheless he was constantly protected and cared for by his network of Limousinaise supporters in the Corrèze, Creuse and Haute Vienne. Known in patois as "Lou Grand", Guingouin also gained the moniker, possibly from a reference by Gabriel Roucaute, one of the leaders of the underground Communist Party in the French southern zone, of "the madman who lives in woods". Police reports in the area though had much more gravity in their description as in their eyes he was "the dangerous communist, Guingouin Georges, on the run... condemned to death in absentia".

Between 1940 and 1942, there was comparatively little out and out fighting between the German occupying forces and the Resistance. For the most part the Resistance carried out intelligence gathering activities and relatively minor sabotage work, along with helping downed airmen escape, but little in the form of direct combat. During this period of time Guingouin went to great lengths to gain at least the understanding and trust of the local non-involved population, rather than their hostility with all the dangers of betrayal which that brought.

As head of an underground printing works, Guingouin was now forced to live under the hardest of conditions, sometimes in shacks and uninhabited houses or even in the undergrowth of the forest. Still, Guingouin continued his work, organizing massive distributions of leaflets at large gatherings such as local fairs and festivals. Not surprisingly, the group's activities were widely denounced in Vichy France both by the police force and by Marshal Pétain, himself, who said that these actions were causing a "feeling of ill wind to rise in all France".

The stakes were raised on 1st October 1941, when Guingouin and his group broke into and stole a stock of ration cards from the town hall in Saint-Gilles-les-Forêts. As a result, and in his absence, on January 21st 1942, Guingouin, for his part in this action is condemned by the Military Tribunal of the 12th Area to serve penal servitude for life. From this point onwards the Resistance group led by Guinguoin, now known as the 'Francs Tireurs' (The Free-Shooters, named after the group involved in the Franco-Prussian war of 1870-71), became much more aggressive in their actions against the German occupying forces.