1. The respondent shall notify the complainant before the end of the reasonable period of time of any measure that it has taken to comply with the arbitration panel ruling.

2. If, at the end of the reasonable period, the complainant considers that the respondent has failed to comply with the arbitration panel ruling referred to in Article 173, the complainant may request the original arbitration panel in writing to rule on the matter. The arbitration panel shall notify its ruling to the Union and the United Kingdom within 90 days of the date of submission of the request.

3. In the event of the original arbitration panel, or some of its members, being unable to reconvene to consider a request under paragraph 2, a new arbitration panel shall be established as set out in Article 171. The time limit for notifying the ruling shall be 60 days from the date of establishment of the new arbitration panel.

4. Where a case referred to the arbitration panel pursuant to paragraph 2 raises a question of interpretation of a concept of Union law or a question of interpretation of a provision of Union law referred to in this Agreement, Article 174 shall apply mutatis mutandis.