Does increasing immigration change the nature of language politics in a party system underpinned by ethnic valence strategies? This paper utilizes qualitative data to illustrate the manner in which debates on linguistic pluralism have become enmeshed in the politics of ethnic defense in Northern Ireland. It will be shown that language politics in this context is driven by the powerful pull of bi-national considerations. This is despite the fact that migrant languages have become increasingly common in the territory. The research provides insight into the manner in which ethnically defined parties have engaged with multicultural diversity, in the context of increasing immigration. It is shown that Sinn Féin representatives largely ignore discussions about wider language diversity, preferring to focus on narratives related to Gaelic. The Democratic Unionist Party (DUP) tends to utilize the broadened range of minority languages as a shield to repel nationalist demands for greater state support for Gaelic programs. The analysis of this evidence suggests that ethnically defined parties are ill-suited to the demands of a multicultural society and immigration-generated diversity.