This article contributes to the growing field of studies on party–protest linkages that highlight the dynamic nature, complementarity and fuzziness of the parliamentary arena and protest arena. Taking the policy field of asylum, it investigates, first, the conditions for the permeability of the protest arena for party activism and, second, the ways in which party activism shapes and transforms the protest arena. The empirical observations refer to Austria, which has a political framework with highly politicized immigration, strong political parties and a weak protest culture. Methodologically, the paper combines a protest event analysis with two in–depth case studies on protests. The authors argue that the openness of the asylum protest arena for parties is characterized by modest protest demands, and depends on the dominant political position as well as the decision making structure regarding the protest issue. The article demonstrates that pro-asylum protests are less open to political parties than anti-asylum protests, which are in tune with the dominant political position on asylum in Austria. The findings also show that anti–asylum protests are not only more likely to attract the involvement of political parties, but also tend to become instrumentalized for party–competitive ends. Pro–asylum protests, in contrast, keep their substantive, grievance–focused orientation even when political parties step in.