© 2017, © The Author(s) 2017. Theorists of left and right agree that periods of crisis are fertile times at which to precipitate change. However, protesters on the periphery of the public sphere must overcome barriers, or what Habermas called ‘sluice gates’, if their discourse is to be publicly and politically influential. This study of newspaper discourse and activity in parliament and the public sphere over a 6-year period takes tax justice campaigning in the United Kingdom as a case study, and in particular protest group UK Uncut’s attempt to mobilise opposition to austerity by advocating a crackdown on tax avoidance as an alternative to cuts. It finds that while UK Uncut successfully amplified arguments previously raised by experts, tra...