The Comintern intervened by means of an open letter to the party in 1929, forcing the removal of the DKP's leadership.
Concurrently, the Great Depression was reaching its peak in Denmark, allowing the DKP to channel rising economic dissatisfaction.
[1][6] A national unity government was formed by the other major parties, which cooperated with the Germans, including in the outlawing of the DKP.
[1][6] Members of the DKP sat on the Danish Freedom Council, the largest underground resistance force against the German occupation.
[6][8] The Social Democrats experienced a rapid decline in influence during this period, remaining outside of the resistance movement for the entirety of the occupation.
[1] While the party was unsuccessful in that effort, the movement successfully forced the Danish government to refuse permission to place NATO air fields in Denmark.
[1] Officially, the DKP's political line did not conflict with that of the CPSU, but pre-war factional tensions continued in the party in the post-war period.
[1] Factional tensions peaked with the Soviet suppression of the Hungarian revolution of 1956, which caused a massive backlash against the DKP,[10] and sparked a split within the party.
[11] Larsen was replaced by Knud Jespersen, a hardline pro-Soviet communist, positioning the DKP as a staunch supporter of the Soviet Union.
The party achieved a resurgence following the 24th Congress of the DKP in 1973, which focused on demanding Denmark's withdrawal from NATO and the EC.
[1] On the back of rising disaffection with the EC and increased popularity amongst student movements, the DKP regained parliamentary representation in 1973 election, taking 3.6% of the vote and 6 seats.
[14] Gert Petersen, then-chairman of the Socialist People's Party, claimed at the time that cooperation between such diffuse ideological currents would fail.
[21] Since 2009, the DKP has been represented in local municipal and regional elections, often in cooperation with the KPiD and KP, two other Danish Communist parties.
[citation needed] In the early 1920s, the party's newspaper was named Arbejderbladet ("The Worker's Paper") and had a circulation of approximately 6,000, but this dropped to around 4,000 by the late 1920s.
[6] Since 2001, the DKP has published the quarterly magazine Skub ("Push") with news related to the party and communism in general.