This paper analyses the nature of collaborative teacher learning as a form of 'public sphere', under current policy conditions. The research draws upon Habermas' notions of communicative action and public spheres, and literature on the nature of teachers' learning in the context of standardized curriculum and assessment reform, to analyse how teachers' work and learning can be understood in light of pressure for increased accountability for improved performance. Drawing upon transcripts of professional learning meetings--referred to as 'Inquiry Cycles'--at a school in northern Queensland, Australia, and interviews with participants, the research reports that while the Inquiry Cycles constituted a 'public sphere' for teachers' learning and inquiry, they were simultaneously influenced by more instrumental policy support for an increasingly prescriptive curriculum, and pressure for improved performance, particularly against standardized measures of literacy and numeracy. The research explores how a public sphere in the form of the Inquiry Cycles was responsive to these more instrumentalist forms of rationality, revealing a need for cautious engagement with such initiatives under current policy conditions, even as they have the potential to effect more productive learning on the part of teachers.