The main goals of the FNC were to present an opposing front to the Spanish State of caudillo Franco and to advocate for Catalan independence.

The FNC was born in April 1940 in Paris as a patriotic front in the hands of several exiled nationalist militants of Estat Català and belonging to all the different sectors that corresponded to the ancient parties and organizations that entered Estat Català when he left Esquerra Republicana de Catalunya [ERC] May 1936.

In August 1940, Andreu, Cornudella, Cruells, Xammar and others entered Catalonia clandestinely and engage in espionage work for Britain.

Jaume Ribas i Surinyac contacted the British Intelligence Service in 1943, who gave them weapons and a radio station, and Gregori Font to the Deuxième Bureau (France).

Manuel Valls de Gomis and Jaume Cornudella i Olivé helped to flee about 800 allied aviators, while Josep Rovira i Canals organized another one for Palafrugell, Vic and Barcelona.

However, when President Josep Irla i Bosch formed his government 14 September 1945 did not consult the FNC, which led to his marginalization in high politics to exile This will make them dump into actions inside.

The September 11 of 1944 a squad led by Martínez and Vendrell hung a sign on the air shuttle from the port of Barcelona.

In January 1946, weapons and explosives passed through the border, which strengthened the military section, while in April Jaume Cornudella and Manuel Valls de Gomis began to emit with a short-wave radio.