This chapter theorizes and empirically studies the relationship between political advisers and civil servants. We start out by clarifying the causal links assumed by Guy Peters’ adversarial model. The factors identified are the partisanship and organizational interests of civil servants, and the competition over policy content between them and political advisers. The importance of these aspects is tested using a survey answered by 801 civil servants and 42 political advisers in Swedish government offices in 2012. We find that there is a noticeable share of civil servants who perceive tensions between themselves as a group and political advisers. Moreover, these tensions can, to some extent, be explained by the factors suggested by the adversarial model. The political advisers, on the other hand, claim that their relationships with civil servants are almost perfectly harmonious, a result that illustrates the methodological problems associated with asking respondents about their own roles and work.