Limiting global warming to well below 2°C requires politicians to introduce contentious legislation to cut greenhouse gas emissions. Creating a political mandate for this is increasingly challenging when policies affect people’s lives directly via increased costs, new infrastructure, or changes to land use, transport or diet choices. Previous studies highlight the crucial but under-researched role of politicians in maintaining the conditions for such climate action. In this study, based on interviews with UK Members of Parliament and a focus group with civil society actors who work directly with MPs, we analyse the period 2018–2023 to examine how politicians have adapted to the rapidly changing political context during this time. This context includes a surge in global climate protests, political polarisation, extreme weather events, and increasingly urgent climate science. We find that climate change has gone from an “outsider” issue that UK politicians promote by stealth, to being mainstream. Most MPs now advocate strongly for climate action in general terms. However, they raise concerns about the pace of change, the impact on people’s lives, and warn of increased polarisation and opposition. We identify how narratives of “pragmatism” are used by politicians to protect a fragile political consensus, to promote incremental rather than transformative change, to defend fossil fuel companies, and to dismiss “extreme” calls for a more rapid climate transition. Our evidence suggests the political language of pragmatism may become a key component of climate delay and non-transformative solutions.