Recent proposals from the US and European left have used the urgent need for climate change action as an opportunity for a “Green New Deal” (GND), involving large-scale public investment into energy, transport and housing systems, with an explicit focus on improving the lives of the working class. Advocates of GND-style policies argue that they are likely to be much more politically popular than conventional climate policies, such as carbon taxes. Yet, little is known about how GND-style policies fare electorally. We hypothesise that they are likely to (re)unite educated, socially and environmentally progressive, urban voters with the traditional working class, increasing the vote share of left-wing parties. We test our hypothesis with the case of the Spanish Socialist Party (PSOE), which won the general election in April 2019 on a GND-style platform, transición ecológica platform. The incumbent PSOE negotiated deals in 2018 within stakeholders in coalmining municipalities in which the regulated closure of the coalmining industry by 2020 was combined with national government investment in coal regions, worker retraining and social welfare assistance. Combining electoral census data at the municipality level and geo-coded data of coalmines slated for closure, we find that mining municipalities have increased their PSOE support between the 2016 and 2019 general elections. Interviews with local stakeholders explore the mechanisms behind the local support of the GND policy and the PSOE party. Our paper provides evidence that combining state-driven climate action with a progressive socio-economic agenda can be a winning electoral strategy.