Botenga studied law at the Université libre de Bruxelles. In 1998 he engaged in the movement advocating for the step-down of then Belgian Minister of the Interior Louis Tobback, following the killing of asylum seeker Semira Adamu by police officers. Later, he participated in workers' mobilization against the close-down of the Forges de Clabecq iron works.
In the wake of the European debt crisis beginning in 2010, Botenga began to become more involved in European politics, participating in actions of political support for Greece. In 2016, he became the political advisor of the European GUE/NGL parliamentary group. He is a member of the Committee on Industry, Research and Energy and the delegation to the ACP-EU Joint Parliamentary Assembly.