The present Research paper explores comparatively the findings of eight case studies which have been produced by INVOTUNES country teams, covering Belgium, Bulgaria, Finland, Germany, Hungary, Italy, Portugal and Sweden. The main goals of this Research paper are:Tt identify the channels through which national trade unions are involved in the European Semester at both national and EU levels; to highlight trade unions’ influence on the agenda-setting, the outputs and the outcomes of the Semester process; and to address the supporting factors and the barriers to trade union involvement in the respective countries.[enter Abstract Body]