Rethinking Co-creation of Digital and Environmental Policy in Systems of Multilevel Governance (RECODE MLG) is a proposal for Horizon Europe on Multilevel governance in times of Digital and Climate Transitions. Our overarching goal is to promote a just, inclusive and democratic transition to a sustainable and digital future by showing how this ‘twin transition’ can be governed effectively within the EU multilevel governance (MLG) system. The project investigates co-creation as a process that can precisely achieve this objective, by proactively involving multiple actors - including policymakers, stakeholders, citizens and volunteers - in a collaborative endeavour, to identify both problems and solutions related to the twin transition. RECODE MLG brings together leading experts on MLG, sustainability politics, digitalisation, co-creation, democratic theory and deliberative innovation with civil society, industry stakeholders and policymaking representatives. It assesses governance structures at three critical sites of twin transition and designs and implements four co-creation labs in order to advance state-of-the-art and produce policy recommendations and a practical ‘tool-kit’ to support inclusive policymaking on twin transition in MLG.