Collaborative networks are gaining momentum in research and practice as a tool to solve complex problems and create public value. While being characterised as self-regulating and relatively autonomous, collaborative networks have been widely recognised to need metagovernance to drive their collaborative process forward. However, limited attention has been paid to how metagovernors exercise power without undermining the capacity of collaborative networks to solve collective problems. To contribute to this knowledge gap, we develop a new theoretical framework based on a cumulative power perspective in the context of the metagovernance of collaborative networks. We outline three modalities of metagovernance (output, input and process) through which metagovernors can exercise power by structurally privileging either their own interests or those on whose behalf they metagovern. We apply the theoretical framework to a Danish case study of collaborative networks in sustainable housing. Through this case, we showcase the repressive and constructive features of power in the metagovernance of collaborative networks. A key research finding is that metagovernors can improve their awareness of how to balance constructively and repressively exercising and distributing power in collaborative networks by understanding the power dynamics entangled in the different modalities of metagovernance.