The party was a junior partner in government in the Seimas, Lithuania's unicameral Parliament, from 2018[6] to 2020. At the time, the LSDDP had 50 sections.[7]
The party scored badly in the 2019 European Parliament election, scoring only 2.4% of votes and failing to elect any MEP. The party won slightly over 3% of the popular vote and 3 seats in the 2020 parliamentary election (only one MP, Andrius Palionis, was reelected). By this, the party became eligible to state dotation, but it was not allowed to form a separate parliamentary group, as a minimum of seven MPs are required for its formation. To do so, the LSDDP aligned with the Electoral Action of Poles in Lithuania, Freedom and Justice (formerly Order and Justice) and independent right-wing deputies Petras Gražulis and Valdemaras Valkiūnas [lt] to form the Lithuanian Group of Regions (Lithuanian: Lietuvos regionų frakcija).
In July 2021 the party adopted the name Lithuanian Regions Party. Jonas Pinskus, a former member of the Labour Party who joined the LSDDP in 2018, was elected chairman. He emphasized taking the party to a regionalist direction and emphasized growing differences between the Regions Party and LSDP.[8]
Pinskus' wife and Mayor of Širvintos, Živilė Pinskuvienė, joined the Regions Party alongside her electoral committee "Živilė Pinskuvienė's team – for a successful Širvintos region" (Lithuanian: Živilės Pinskuvienės komanda – už sėkmingą Širvintų kraštą) in 2022.[9] The Regions Party gained 73% of the vote in Širvintos in the 2023 Lithuanian local elections,[10] the only municipality in which the party earned the largest share of the vote.
