What is the difference between the proposed Parliamentary Assembly and the Inter-Parliamentary Union?

The Inter-Parliamentary Union is an independent association of national parliaments with a principle goal of strengthening the ability of national parliaments to exercise an oversight function of international activities at the national level. The purpose of the proposed Parliamentary Assembly by contrast is to exercise parliamentary functions directly at the international level, in its own right. One of the goals is to make UN executives and UN institutions accountable to a global parliamentary body. There is currently no interest by the IPU in assuming such a capacity.