Public opposition to long-term policies often hinders investment in public goods such as climate change mitigation. The challenge stems from high upfront costs and long implementation periods, which increase the uncertainty associated with policymaking. Previous research highlights the potential of policy design, information provision, and actor involvement to address these challenges. However, the role of actor involvement during policy implementation remains underexplored, even though this stage of the policy cycle introduces the most uncertainty into long-term policymaking. This study examines whether involving different combinations of actors in policy design and implementation can reduce opposition to long-term versus short-term policies. Public administrations, often seen as polarized and influenced by elected officials, may lack the perceived impartiality and accountability needed to build credibility. However, experts, who are perceived as knowledgeable and independent, and citizens, who can enhance accountability, can address these shortcomings. In particular, their involvement in the policy implementation phase may therefore mitigate public opposition to long-term policies more than the involvement of the public administration. To test these expectations, the study conducts a choice experiment in Germany (N=2000). The experiment focuses on CO₂ storage projects, a climate change mitigation strategy with localized costs and varying monitoring requirements (i.e., 2-40 years). Respondents are exposed to randomized combinations of actors (i.e., bureaucrats, experts, and citizens) involved in planning and monitoring activities for CO₂ storage projects with different monitoring duration requirements.