Purpose-The need to alleviate poverty and achieve the United Nations (UN) 2030 Sustainable Development Goals (SDGs) through Universal Social Protection (USP) mechanisms is a high priority for governments and international organisations (IOs). This paper focuses on the recent introduction of a general minimum income (GMI) in Greece, in the context of the international diffusion of governing expertise. It examines whether the "universal" scheme being implemented constitutes a paradigm shift likely to offer solutions to the country's previous fragmented and unjust welfare system, and to problems the society has faced since the 2010s depression. Design/methodology/approach-The paper uses critical grounded theory, with data gathering through iterative field observations and semi-structured interviews. Findings-Results highlight the elusiveness of USP normative promises: rather than enhancing people's effective freedoms to act as self-determining agents, USP pushes the poor to adapt to current degraded socioeconomic conditions. Participation in the shadow economy is a structural feature of USP; it is implicitly tolerated insofar as it is regarded, in the words of the World Bank (WB), an "engine for growth". This constitutes an institutional and governance challenge for the implementation and expansion of social welfare programmes and could compromise the 2030 SDGs Agenda. Originality/value-While research to date has examined the "modernisation" of the Greek welfare system in a national or comparative perspective, it adds to the literature by framing the study in the field of global social policy, shedding light on the discrepancies between internationally designed mechanisms and the normative aims of USP.