Interest in cooperative organisations has increased in the midst of financial and environmental crises, as cooperatives are presented as organisations capable of fostering economic stability, social inclusion and environmental protection. However, scholars have noted how several cooperatives from the early twentieth century have become increasingly similar to competing investor-owned firms, in what has been described as a process of degeneration. This has raised questions regarding whether cooperatives can maintain social and transformative ambitions within competitive market environments. Using an ideal-type methodology based on three competing cooperative rationalities, this thesis analyses how cooperative principles were discursively rearticulated within Lantbrukarnas Riksförbund, the main interest organisation for agricultural cooperatives in Sweden, during a period of institutional upheaval between 1989 and 1995. The findings suggest that cooperative principles were rearticulated in ways that legitimised increased internal competition and market adaptation, in what may be understood as a process of degeneration – although neither straightforward nor complete. In contrast to accounts portraying the farmers’ movement as largely pushed towards market adaptation by external forces, the findings highlight the role of agency, strategic decision-making and the adoption of neoliberal ideas within the cooperative movement itself. Therefore, this thesis argues that cooperatives should be understood in relation to their specific historical and institutional contexts, with particular attention directed towards changing cooperative rationalities and organisational agency.