How can a Parliamentary Assembly at the United Nations be established?

A Parliamentary Assembly at the United Nations could be set up as a subsidiary body by a vote of the General Assembly under Article 22 of the UN Charter. Alternatively, it could be created on the basis of a new international treaty between governments followed by an agreement that defines its relationship with other UN organs and agencies. Thirdly, as part of a reform of the UN Charter the assembly could be enshrined directly in an amended and re-structured UN system.