​The December Plenary session marked the end of the CoR’s 25th-anniversary celebrations.

The final ceremony was held during the Plenary session and gathered former CoR Presidents and representatives of other European institutions (European Parliament, Commission and Economic and Social Committee) who witnessed and influenced the history and development of the committee over the last 25 years and its growing influence in the inter-institutional context. It was also an opportunity to discuss the way local and regional authorities could enrich the work of the European Union in the future, starting with active involvement in the Conference on the Future of Europe.

​Former EA Group Presidents Seán Ó Neachtain (1998-2002) and Stanisław Szwabski (2015-2017) also attended the ceremony and the EA Group's meeting where they took the members through some historical achievements of the EA Group and proposed ideas on how to develop and reinforce the CoR's position in the future. Mr Ó Neachtain stated the importance of working together within the CoR and that in the face of rising Euroscepticism it is crucial to work effectively with the European Parliament.