Traditionally, debates on EU legitimacy have centred on the tension between democratic representation and the Union’s ability to produce effective policies. Since the late 1980s, however, the multilevel governance (MLG) framework has shifted attention towards legitimacy generated through decision-making processes. From this perspective, legitimacy emerges from structured interactions between different levels of government when formulating and implementing policies aimed at shared objectives. However, the progressive expansion of conditionality instruments since the Multiannual Financial Framework (MFF) 2007–2013 has reshaped the governance architecture of cohesion policy, increasingly constraining the role of sub-state governments in its decision-making and implementation. At the same time, the partnership principle has failed to meet the expectations of subnational governments.

The following overarching research question emerges from this context: To what extent does multilevel governance affect the political legitimacy of the European Union? Building on this, our paper formulates a more specific question: To what extent has the expansion of conditionality mechanisms in EU cohesion policy between the MFF for 2000–2006 and the MFF for 2021–2027 reduced the participation of sub-state actors in the design of the policy and its implementation?

To assess the participation of sub-state governments in decision-making processes, we examine their involvement in negotiations at both the EU and domestic levels regarding the design of cohesion policy for the MFF 2000–2006 and MFF 2021–2027. To measure throughput, we consider transparency, accountability, openness and inclusiveness in the implementation processes of cohesion policy during the MFF 2000–2006 and MFF 2021–2027.

In our analysis, we focus on the following case studies: Germany, Poland, and Spain (two subnational units per country).

Our paper aims to generate practical and theoretical knowledge that will contribute to the debate on the evolution of MLG in the EU, using cohesion policy as an example, as well as its future in the MFF for the period 2028–2034.