Abstract. Radical right nativist parties have gained ground across Europe in recent decades. However, a key unanswered question is how these parties adapt in contexts marked by the centre–periphery cleavage and competing national attachments. This paper addresses that question by examining the case of Catalonia and the emergence of Vox, a Spanish nationalist radical right party, and Aliança Catalana, a pro-independence, anti-immigration, and Catalan nationalist party. Although both parties align on immigration and economic concerns, they diverge on gender, climate change, LGBT + rights, and – most notably – the national cleavage and territorial issues. Voters from both parties exhibit similar socioeconomic characteristics and share concerns related to immigration, but their national attachment primarily influences their choice between AC and Vox.