He began working closely with the Catholic priest Walter Hogan, and the two founded the Institute of Social Order in 1946, Tan becoming its secretary.
The institute aimed to promote positive relations between workers and management.
For their role in organizing unions, Tan and his colleagues were soon tagged as communists.
In 1998, Tan suffered a stroke, standing down from his role in the FFW, and switching to become commissioner of the Social Security System.
He remained president of the Brotherhood of Asian Trade Unionists, serving until his death in 2005.