The New Zealand (NZ) government, under Prime Minister Helen Clark's Labour-led administration, sought in 2007 to move government core organisations towards carbon neutrality. In late 2008, the NZ government changed from a Labour-led to a National-led (traditionally more conservative) government, and this saw a shift in its carbon neutrality agenda, including the dismantling of the NZ Carbon Neutral Public Service (CNPS) program. In this paper, we explore the experiences of public servants from the lead core agencies involved in the CNPS program to investigate the rise and fall of the program in a time of political change, and to assess the evidence for Cabinet Minister Dr Nick Smith's rationale for program termination. Our research approach comprises a series of semi-structured interviews with the lead core agencies involved in the CNPS program, as well as the program champion, former Prime Minister, Helen Clark. We find that, in spite of initial challenges, the CNPS program appeared to deliver emission reductions, financial cost savings and a range of non-financial benefits. Whilst program costs would have likely outweighed the financial savings, due to high set-up and offsetting costs, we conclude that Nick Smith's case is unsupported by the evidence.