He was named Minister of Finance in September 1936 in the government of Francisco Largo Caballero. As the finance minister, he built up the "Carabineros" (custom guards), a force of 20,000 men which was later nicknamed the "Hundred Thousand Sons of Negrín" (an allusion to the Hundred Thousand Sons of Saint Louis), in order to recover the control of the French frontier posts, which had been seized by the Confederación Nacional del Trabajo (CNT). He took the controversial decision to transfer the Spanish gold reserves to the Soviet Union in return for arms to continue the war (October 1936). Worth $500 million at the time (another $240 million had been sent to France in July), critics argued that this action put the Republican government under the control of Joseph Stalin.