On 23 March 2018, the European Council, meeting in an EU27 format, adopted the guidelines on the framework for a future relationship with the UK after Brexit. As noted in a release on the meeting, the guidelines will serve as a mandate for the EU negotiator to start discussing the framework for the future relationship, with the aim of reaching a common overall understanding with the UK. That understanding will be reflected in a political declaration accompanying the withdrawal agreement and referred to in it. With respect to taxation, the guidelines include that the future relationship should include robust guarantees to ensure a level playing field to prevent unfair competitive advantage that the UK could enjoy through undercutting of levels of protection with respect to, inter alia, competition and state aid, tax, social, environment and regulatory measures and practices.