In 1928 the party started operating more openly, and contested the 1928 Saeima elections through a proxy list known as the "Left Trade Unions".

They reformed the following year to contest the next elections as the "Trade Union Workers and Peasants Group", winning six seats.

[4] In 1936, a youth organization parallel to the LKJS, Workers' Youth League of Latvia (LDJS), was formed as a cooperative effort by the LKP and their former rivals, the erstwhile Menshevik Latvian Social Democratic Workers' Party, outlawed following the Ulmanis coup d'état in 1934.

After the Soviet occupation of Latvia in June 1940 and the ousting of the Ulmanis government, the LKP and LDJS were legalised again and could operate openly.

[5] Article 6 of the Latvian SSR Constitution (1978) made the LKP's monopoly on political power in Soviet Latvia explicit.

On 14 April 1990, a pro-independence faction under Ivars Ķezbers split off from the LKP to form the Independent Communist Party of Latvia (Latvian: Latvijas Neatkarīgā komunistiskā partija).

The main body of the LKP, under the chairmanship of Alfrēds Rubiks, remained loyal to Moscow and the CPSU leadership.

[10] While the LKP leadership was in exile in the USSR during the interwar years and the Nazi occupation in World War II, Cīņa was published in the Russian SFSR.