In 1935, he joined a number of Confederación Española de Derechas Autónomas (CEDA) deputies of the Cortes in a right-wing coalition led by José María Lamamié de Clairac y Colina in support of their landowner-dominated traditions and specifically in opposition to a law from Manuel Giménez Fernández (also a CEDA diputado) which provided that peasants who had worked land for twelve years were given the opportunity He was not able to win a seat in the elections of February 1936.
[1][2][3] When the Spanish Civil War commenced in 1936, he rejoined the army on 18 July under general Gonzalo Queipo de Llano, commanding groups of falangists operating in working-class suburbs of Seville with artillery fire.
Alarcón de la Lastra directed artillery which bombarded towns as part of the Nationalists' advance; bombing from the air was also used.
Alarcón de la Lastra was thereafter involved in all actions on the march to Madrid, including the Battle of Badajoz and the capture of Toledo.
This advance was later under the command of Juan Yagüe (known as the "Butcher of Badajoz" after that particular ensuing massacre), whose forces had joined the Nationalists from Ceuta.
[1][2][3] In March 1939, Nationalist victor Franco rewarded him by making him governor of Madrid and in August Minister of Industry and Commerce until 1940.