This study examines the parliamentary debate regarding the proposition "Ny kärnkraft i Sverige - Ett första steg" which aims to facilitate the expansion of nuclear power in Sweden. The purpose is to provide an understanding of the nuclear power debate in the Swedish Parliament since it has been revived by the energy crisis in 2021 and Russia's invasion of Ukraine. The debate is analyzed through a qualitative content analysis to identify the arguments of Tidöpartierna and the opposition for and against the proposition. The identified arguments are then interpreted through the social identity perspective to explain their different standpoints. The results show that nuclear power is a divisive issue in the Swedish Parliament. Interpretation through social identity theory reveals that the parties' historical positions, their perception of which arguments are most effective to attract voters, and confirmation bias influence their views on the nuclear power issue. The conclusions indicate that it is an issue that divides the Parliament into two sides: Tidöpartierna and the opposition parties, with each side presenting different solutions to the energy issue. Tidöpartierna argues for an energysystem where nuclear power complements renewable energy sources, while the oppositionparties favor a solution where the energy system is solely based on renewable energy sources.