In this article, I ask how senior civil servants (SCSs) practice functional politicisation. The literature suggests that they balance responsiveness with astuteness towards ministers, while maintaining neutral competence. However, functional politicisation is prone to affect this balance. Drawing on 160 h of ethnographic shadowing in Dutch government, I show three faces of functional politicisation; while directly advising ministers, in the preparation of policy advice and while working in the public eye. The findings suggest that senior civil servants actively try to align their fellow civil servants with their version of the minister’s wishes. This practice of ‘proxy politics’ calls for a shift in functional politicisation research from political ‘skills’ to ‘authority claims’ among senior civil servants. I conclude with urgent implications for politicisation theory and civil service practice.