BP and the TTIP

From the Washington Post:

The British government has taken the unusual step of filing a brief in a Texas federal court in support of BP in its quest to get the Environmental Protection Agency to lift a ban on the British oil firm’s ability to bid for federal contracts, including leases on new offshore drilling prospects in the Gulf of Mexico.

“It is the view of Her Majesty’s Government that EPA’s disqualification and suspension of multiple BP entities may have been excessive,” the government said in its amicus brief filed with the U.S. District Court for the Southern District of Texas. Given BP’s efforts to settle oil spill claims, the British government said that the EPA’s prohibition, “if upheld, could undermine the corporate culture of responsibility all responsible governments have sought to foster.”

So here's a situation where the UK is espousing BP's claim on a matter related to foreign investment.  If the TTIP comes into effect with the usual investor-state provisions, BP could espouse its own claim directly.  (The arguments quoted certainly sound like FET-type claims).  Would that relieve any U.S./UK tensions on the matter?  Would it lead to a different kind of tension, as BP would be challenging U.S. environmental regulation before an international tribunal?