Erlander was elected to the municipal council in Lund in 1930 and became a member of parliament in 1932, and was appointed a State Secretary at the Ministry of Social Affairs in 1938. As State Secretary at the Ministry of Social Affairs, Erlander was one of the most senior officials responsible for the establishment of internment camps in Sweden during World War II. In the camps, which were kept secret to the Swedish public, people from various ethnic minorities as well as political dissidents were interned, particularly Communists and Soviet Union sympathisers.