I don't read absolutely everything there is to read on ISDS, so maybe this proposal from U.S. Rep. Sander Levin is out there already and has been dicussed to death, but it was new to me:
TPP should include several new provisions to protect the rights of sovereign nations [in relation to ISDS], including: ... (3) ... a mechanism for the TPP countries to agree on an interpretation of an investment obligation, including a decision that a claim submitted to arbitration is not a claim for which an award in favor of the claimant may be granted by the tribunal
What does that last, italicized part mean? It sounds like the TPP governments could step in and block a claim they did not like. It's not clear how exactly this would work. Would they review and approve all TPP ISDS claims, kind of like a GATT/WTO-style panel establishment process? Or would they just, on an ad hoc basis, put a stop to claims that had gotten particularly bad publicity? Would it have to be a unanimous decision, or is a majority enough?
Not that this is likely to go anywhere, of course, but interesting nonetheless.