This paper explores the construction of populist narratives on labour in post-revolutionary Iran. Through the analysis of official May Day speeches given by the leaders of the Islamic Republic between 1979 and 2009, it tracks and investigates the shifting meanings of the words “the people” and “the nation” when connected to workers. Drawing on primary sources in Persian and on field research conducted in Iran between 2017 and 2018, this paper shows how and why – from the Ayatollah Khomeini to Mahmoud Ahmadinejad – workers’ grievances were cast respectively under the Islamic and populist/nationalist umbrella. Moreover, it addresses the following questions: how did this process of discursive absorption work? Why did the IRI’s leaders resort to this expedient of appropriation? Gazing at the historical context as a terrain of discursive wars allows to better frame these issues. Following its foundation in 1979, the Islamic Republic of Iran, under the guidance of Ayatollah Ruhollah Khomeini, began a massive campaign geared to construct a morally guided imaginary of labor as a “religious obligation” and of workers as “holy warriors” for the nation engaged in a war with Iraq, under the auspices of Islam. In this paper, I argue that integral part of this endeavour was triggering a process of appropriation of May Day, which represented a historical symbol of the secular left, through the construction of new collective imaginaries for workers, seen as part of the community of believers. What happened almost thirty years later? Another crucial step was taken. By promising to give the revolution back to the downtrodden, the benefits of oil revenues to “the people,” and social justice to urban poor, Mahmoud Ahmadinejad won the elections in 2005 against former president Rafsanjani. Social justice [edaalat-e ejtemai] for all human beings [ensan-ha] was a recurrent theme in the president’s rhetoric. Nevertheless, as this analysis explains, Ahmadinejad populist discourse over workers suffered of deep contradictions both in language and in facts, as labour strikes were harshly repressed. Finally, I argue that through the strategy of casting workers under the populist umbrella, Ahmadinejad de facto disempowered the workers’ potential as a class and deprived social justice of its historical meaning to labourers.