AbstractTo date, research on politicians’ influence on the work of street‐level bureaucrats (SLB) and the consequences for policy implementation has mainly focused on disruptive effects of political involvement—for instance, poorer social equity in public service provision or political patronage. Our study opens up this perspective and argues that the relationship between politicians and SLB is a two‐way relationship shaped by capacities of the stakeholders themselves and their organisational environment. We link SLB research with policy capacity literature. We focus on the effect of political capacity because this type of capacity meaningfully influences whether SLB can actively control the relationship with politicians. We ask: What is the relevance of political capacity for policy implementation? We use data from Swiss social assistance where the phenomenon of interest, that is the political involvement, is institutionalised by law within the implementing agencies. We show that political capacity at the organisational and individual level has a confidence‐building effect. SLB and politicians learn how to engage with each other and how to make the most of the exchange. Politicians gain a deeper understanding and are able to politically legitimise the policy.Points for practitioners Existing research on politicians’ influence on the work of street‐level bureaucrats (SLB) has mainly focused on disruptive effects of political involvement—for instance, poorer social equity in public service provision or political patronage. We show that the relationship between SLB and political actors can actually lead to ‘non‐disruptive’ or even positive effects on public service provision due to certain capacities of the stakeholders themselves and their institutional environment. We identify two types of capacity that foster a constructive relationship between SLB and politicians: organisational and individual political capacity. Organisational political capacity: The institutional or organisational setting within which SLB and politicians implement public policy and provide public services can promote regular exchange and cooperation between these two types of stakeholders to a greater or lesser extent—or even require it (e.g. by law). If the setting is conducive, constructive contact between SLB and politicians takes place during policy implementation. Thus, SLB and politicians know each other and know how to interact, which enhances trust among them and mutual understanding of their respective duties, challenges, and interests. Individual political capacity arises from this as SLB learn how to use this contact for their needs, that is to obtain and sustain political support for their policy actions. Politicians also benefit from the exchange because they gain a deeper understanding of the respective policy and feel more confident in representing it towards the public and the politics. In short, the findings show how capacity at different levels may reinforce each other. The organisational context can promote political capacity through regular contact between SLB and politicians. Actors have to learn to work with each other and thereby enhance their individual political capacity.