Debates over the stripping of citizenship have been rekindled in many countries in recent years. Radical right populist parties (RRPPs) are often perceived to have played a significant role in these resurging debates, even when they do not possess executive power and are often marginalised by mainstream parties. Thus, RRPPs’ real influence on policy-making remains unclear and the way RRPPs intervene in the policy-making process to influence it has not yet been satisfactorily determined. By focusing on policy-making, this study asks the question: how do RRPPs influence resurging debates over the stripping of citizenship? Using process-tracing and evidence from archives, memoirs and 67 interviews with policy-makers and party leaders, this research aims to determine if and how RRPPs intervene in the process in France and Belgium. The results indicate that RRPPs matter but that their influence is strongly curtailed. Their influence is not exercised directly and through institutional arenas, but indirectly: based on a provocative style, in a specific context, and through public opinion and the media.