It should be obvious to long-time readers that I am concerned about policy space and regulatory autonomy under trade and investment agreements. However, I have doubts that the "right to regulate" is a good way to describe the issue:
Talk of "rights" can be unproductive when carried out with a lack of precision, and that is what is going on here. When domestic regulation intersects with international economic law, the underlying issue is the scope and extent of the constraints imposed by international law, and the allocation of power between the national and the international. International law can certainly interfere with the ability of governments to regulate; indeed, that might be the point of it. But different international law rules interfere in different ways. If narrowly drawn (anti-protectionism), they do not interfere much at all; if written broadly (non-arbitrary regulations), they interfere a lot. If we fail to distinguish between the two, we get a confused and unhelpful debate, with people talking past each other. How international economic law affects the ability of governments to regulate is an important question to deal with. Let's not obscure it by referring vaguely to a "right to regulate," without addressing the nuances of the issue.
More here. I'm sure some people will disagree with me. Feel free to let me have it in the comments!