While the union was not affiliated to the General Commission of German Trade Unions or any other federation, most of its officials were members of the Social Democratic Party of Germany, while the Berlin region became increasingly dominated by members of the Communist Party of Germany (KPD) and Independent Social Democratic Party of Germany.
It proposed a merger into the Union of Municipal and State Workers (VGS), but this was rejected on a split 22-22 delegate vote.
[3] In 1929, the VGS was finalising a merger which was to form the General Union of Public Sector and Transport Workers.
The firefighters voted in favour of joining the new union, completing the merger on 1 January 1930.
However, much of the KPD opposition refused to join the new union, instead transferring to the German Civil Service Federation.