Welz, active in various initiatives and ad hoc groups of the East German opposition and the peace movement was co-founder of the oppositional political group Democratic Awakening in 1989.
Welz, aktiv in verschiedenen Initiativ- und Ad-hoc-Gruppen der Opposition und Friedensbewegung, war 1989 Mitbegründer der oppositionellen Partei Demokratischer Aufbruch.