Subsidiarity means that decisions within the EU should be taken at the closest practical level to the citizen. In other words, the EU should not take on tasks which are better suited to national, regional or local administrations.
Building upon the previous EU Treaties, the Lisbon Treaty formalises the CoR's role as the defender of the principle of subsidiarity, giving the Committee the right to bring a case before the European Court of Justice if it believes the principle has not been observed.
The CoR has adapted its rules of procedure to this new prerogative and is further developing its subsidiarity monitoring system, particularly the activities of its Subsidiarity Monitoring Network.
Read more about activities of the Subsidiarity Monitoring Network