What impact has the British EU in/out debate had on British diplomacy in Brussels? Has it reduced the ability of British diplomats to be included in informal meetings with other diplomats as well as reduced their leverage in the Council ? Based on semi-structured interviews with diplomats from 15 permanent representations in Brussels, this paper examines the consequences of the current British in/out debate for British diplomacy in the EU. The paper is based on diplomats’ perception of the UK’s (changing) role in the Council since the debate of a possible referendum on British EU membership started in 2012. Theoretically, the paper marries insights from Putnam’s two-level game with reputation theory. The paper shows that several permanent representations in Brussels have started to exclude British diplomats from informal meetings because they perceive the UK as an uncommitted EU-member.