Following Saarland's accession to the Federal Republic of Germany, the party was constituted as the Saarland regional association of the League of Germans [de] (Bund der Deutschen, BdD) on July 7, 1957, but did not formally dissolve.
The DDU won two seats in the 1960 Saarland state election [de].
On March 5, 1961, a Saar regional branch of the German Peace Union [de] (Deutsche Friedens-Union, DFU) was constituted under the leadership of Gieseking, who was also chairman of the DDU and a founding member of the DFU.
The DDU thus functioned “de facto”, according to Rolf Schönfeldt, as a regional association of the DFU, but again did not formally dissolve.
In 1968, they ran in the Saarland local elections and won a total of 47 seats, before merging with the DFU.