Founded on 2 October 1989, only a few weeks before the fall of the Berlin Wall, the United Left demanded a reformation of socialism with the stated goal of creating a free and democratic GDR.

In contrast to other East German opposition groups, the United Left received less support from Western governments and political parties.

Organisational issues and internal tensions between the various ideological factions meant that the United Left only achieved limited political success during its existence.

At the first free elections in the GDR in March 1990, the United Left started together with "Die Nelken [de]" ("The Carnations"), a Marxist party.

The electoral alliance with the name "Aktionsbündnis Vereinigte Linke [de; nl]" gained 0.18% of the votes and one seat in the Volkskammer, which would be held by Thomas Klein.