The aim of this study is to use the concept of ‘mediatization’ to inform a critical, grounded and fine-grained empirical analysis of the institutional dynamics that operate at the interface between government and the media in a liberal democracy. This thesis applies a novel theoretical and empirical approach to the familiar narrative of ‘political spin’, challenging the common assumption that government communications is either a neutral professional function, or an inherently unethical form of distorted communication. In May 1997, Labour came into power on a landslide, bringing into government its 24/7 strategic communications operation, determined to neutralise what it saw as the default right-wing bias of the national media. In the process, the rules of engagement between government and the media were transformed, undermining the resilience of government communications and unleashing a wave of resistance and response. Much academic attention to date has focused on party political news management, while the larger but less visible civil service media operation remains relatively un-examined and undertheorised, although some northern European scholars are exploring mediatization from within public bureaucracies. This study takes a qualitative approach to analyzing change between 1997 and 2014, through 16 in-depth interviews with former, largely middle-ranking, departmental government communicators, most of whom had performed media relations roles. This was a group of civil servants that had spent their working lives in close proximity to ministers during a time of rapidly increasing media scrutiny. These witness accounts were augmented by interviews with six journalists and three politically-appointed special advisers, together with a systematic analysis of key contemporary and archival documents. The aim was to provide insights into change over time within a shared policy and representational space that is theorised here as the ‘cross-field’, where media act as a catalyst for the concentration of political power. What can and does government communication in its current form contribute to the democratic ideal of the informed citizen?