In the same year his co-workers elected him to the works council and as the youth spokesman in the local Building Workers' committee.
In 1947 he joined the country's ruling Socialist Unity Party of Germany (SED / Sozialistische Einheitspartei Deutschlands).
In October 1953, however, he was removed from his position as deputy chairman and received a formal warning (Partreistrafe) from The Party on account of a "false assessment" in June 1953 and for his "support of the programme of demands put forward by the IG Bau-Holz union"[3] in July 1953.
From 1958 right up until February 1990 Lindner was also chairman of the national committee for his union, IG Bau-Holz in succession to Walter Tille.
[1] In 1976 Lothar Lindner was nominated as a candidate for membership of the ruling SED (party) central Committee.