Political communication is central to the electoral ascension of populist parties across the world. Several studies investigate how communication is used by populists to gain power, but we know very little about how the communication varies when moving between opposition and government office. The few studies on the topic focus exclusively on right-wing populist parties and neglect left-wing populism. This article addresses this gap in the literature and analyses the political communication of left- and right-wing populist parties by comparing their periods in opposition and in government. It focuses on the Northern Ireland case and compares Sinn Féin and the DUP and uses deductive thematic analysis for each election manifesto for the Northern Ireland Assembly between 1998 and 2022. The analysis includes four themes: people-centrism, anti-elite bad manners, crisis talk and volonté générale solutions. Contrary to theoretical expectations, we find that the right-wing populist DUP has changed more substantively its political communication than the left-wing Sinn Féin when moving from opposition to government.
