During an internal power struggle in the early 1950s he was ousted from the leadership of the Spanish Communist Party (PCE), but was later rehabilitated.

In the first months of the Spanish Civil War, which began in July 1936, Antón was active in spreading propaganda in the 5th Regiment.

[4] The Popular Front's Comité Provincial de Investigación Pública (CPIP) became the center of a revolutionary terror network targeting Fascist suspects.

Antón redefined the role of the brigade commissars in the Army of the Center as being to prevent panics and to reestablish order.

He also told commissars and political delegates that they should remove distinctive badges, which made them favored targets for enemy snipers.

In October 1938, Antón was assigned responsibility, with Palmiro Togliatti and Gyula Alpári, for conducting an international campaign to discredit the anti-Stalinist Workers' Party of Marxist Unification (POUM) as counter-revolutionary Trotskyites.

[11] In February 1939 Antón was in Toulouse, as were Antonio Mije, Luis Cabo Giorla, Santiago Carrillo and Enrique Líster.

Most of the exiled PCE leaders were welcomed by the USSR, making their way by boat from the northeast of France, including Ibárruri, José Díaz, Jesús Hernández Tomás, Juan Modesto, Enrique Lister, Irene Falcón, Antonio Mije, Vicente Uribe and Santiago Carrillo.

After the German invasion of France, at Ibárruri's request the Russians obtained Antón's release and transfer to Moscow.

[1] Dolores Ibárruri temporarily withdrew from the PCE leadership due to sickness in the summer of 1947, and Vicente Uribe and Antonio Mije began feuding with Antón and Santiago Carrillo.

According to Líster his behavior included "crude and brutal anti-Leninist means of leadership, as well as vanity and blind ambition."