As a sitting Justice, I would amend the clause to

The Court Justices are not prohibited from joining the Assembly or any associated organization in the South Pacific, insofar as their involvement does not cause undue influence to be imposed or the corruption of the Courts in the discharge of their duties.

Someone tidy this up for me please. My intention is to allow the Justices to participate politically, while preventing any CoI due to such participation that may negatively influence them and affect the discharge of their duties.