In May 1921, Philipp Dengel joined Die Rote Fahne newspaper, which by this time had become a Communist Party publication, as foreign policy editor. The next year, he was switched to work as a senior journalist with newspapers backing the party in Germany's principal industrial regions further to the west. In 1922, he took over as editor in chief at , the Communist daily newspaper produced in Cologne. By 1923, he had moved again, and was looking after the . He took part in the October uprising in the city, taking on key organisational responsibilities for munitions and food supplies.