The implementation of strategic decisions is a complex and demanding process that requires an open and lateral communication of free-flowing information to make sense of and champion a firm's intended changes. For the process to be effective, middle managers need to operate within an environment that nurtures a pro-social mindset and helps to cope with stressors caused by the possibility of harm done by the intended changes to their vested interests. Drawing from the job demands-resources model, we argue that organisational politics represent an organisational demand, which may hinder the implementation of strategic decisions. To cope with this demand, implementers recruit organisational resources (i.e. trust in the top management team) that may moderate the negative effects of dysfunctional politics. To test our hypotheses, we drew on a sample of 228 middle managers from 114 private Greek firms with more than 100 employees across various industries. We found that when organisational politics were high during the implementation process, implementation success diminished. However, their negative impact was reduced when trust in the top management team was high. Conversely, when organisational politics were low, middle managers reported a higher implementation success regardless of how highly the top management team was trusted. Our study is the first to test the influence of organisational politics on the success of the implementation process from a middle manager's perspective. In addition, we show that implementation success can be viewed through a demands-resources lens, which provides a meaningful contribution to research on strategy implementation.