Schleswig-Holstein Question
Krieger was elected to the constitutional assembly in 1848 representing the National Liberal Party. He advocated delaying processing the proposal for the constitution until representatives for Schleswig could be elected — the outbreak of the First Schleswig War had rendered this impossible and the proposal was renamed from "Constitution for the Kingdom of Denmark and Schleswig" to "Constitution for the Realm of Denmark" instead. Krieger was a supporter of the so-called "Eider-Danish" doctrine which would involve "Danification" of the Duchy of Schleswig (and neither the Duchy of Holstein nor the Duchy of Lauenburg) and which dominated the national liberal politics on the Schleswig-Holstein Question.