On 8 August 1937, Major General García Pallasar had received a note from Generalísimo Francisco Franco which expressed the need for a Panzer I armed with a 20 mm gun.
Den 8. august 1937 havde generalmajor García Pallasar modtaget en note fra Generalísimo Francisco Franco som udtrykte behovet for en Panzer I udstyret med en 20 mm kanon.