Brussels is home to one of the highest concentrations of political power in the world and the revolving door is one of the most important ways in which lobbyists can influence the political agenda in Brussels. When senior European decision-makers leave office and go straight into lobby jobs, or when lobbyists join the EU institutions, the risk of significant conflicts of interest is great, undermining democratic, public-interest decision-making. CEO is working with the Alliance for Lobbying Transparency and Ethics Regulation (ALTER-EU) to challenge the revolving door and to demand that it is effectively regulated.