This thesis describes the system of submitting observations envisaged in Article 23 of the Protocol on the Statute of the European Court of Justice. The thesis seeks to illustrate and criticize the utilization of the system enshrined in Article 23 by the member states of the European Union. The experience of the United Kingdom is analyzed by examining the preliminary ruling judgments that the government of the United Kingdom has submitted observations in order to describe the system and demonstrate its application by a member state of the European Union.