It developed out of the wing of the Socialist Party of Labour (PSM) that objected to the merger of PSM with the Social Democratic Party (PSD) in July 2003 and wanted the PSM to continue as a socialist party.

The Romanian authorities did not recognize this group as part of PSM, and instead it took the name Socialist Alliance Party.

PSR was a founding member of the Party of the European Left.

However, much like its predecessor, it is nationalist and supports Communism nostalgia.

[5] However, it strongly rejects the Romanian membership in NATO.