A process for increasing the adhesion of a polymeric material to a metal surface, the process comprising contacting the metal surface with an adhesion promoting composition comprising: 1) an oxidizer; 2) an inorganic acid; 3) a corrosion inhibitor; and 4) an organic phosphonate; and thereafter b) bonding the polymeric material to the metal surface. The organic phosphonate aids in stabilizing the oxidizer and organic components present in the bath and prevents decomposition of the components, thereby increasing the working life of the bath, especially when used with copper alloys having a high iron content.