Citizen participation is key to learn of actors' lived experiences for the design of just energy policies. Many members of society, however, experience barriers to participation. As a result, the injustices they experience are likely to remain hidden from public decision-making processes. This paper applies the 'hidden morality' framework to a case study of migrants with a low socio-economic status (SES) in the Dutch city of The Hague. Through the analysis of 15 policy documents and 26 semi-structured interviews with migrants in a low-SES neighbourhood, this paper uncovers hidden injustices and the societal mechanisms forming barriers to participation. Simultaneously, the case study is used to test the conceptual framework. The study reveals that the interviewed low-SES migrants were not only considerably prevented from expressing their perceived injustices in decision-making, but were also unaware that they were subject to several procedural injustices. We identify three main barriers withholding low-SES migrants from participating in decision-making: unfamiliarity with (Dutch) democratic institutions and of their rights as citizens; language barriers; and weak social ties in their neighbourhoods. We conclude that the hidden morality framework proves useful for revealing injustices and barriers to participation that would otherwise run the risk of remaining hidden from scholars and policymakers.@en