Last year a major BuzzFeed News investigation showed how secretive ISDS arbitration panels had overturned prosecutions of corporate executives and reversed environmental laws, and also shed light on the secretive operations of the systems, which generally don't rely on fixed panels of full-time judges, instead using lawyers as arbitrators – some of whom have previously acted for the companies concerned.



In the UK, opponents to deals including ISDS – primarily anti-TTIP or -CETA activists – have warned that such trade deals could see corporations challenging the NHS as unfair competition to private health providers, or challenging UK animal welfare and food safety rules, including those banning GM foods and chlorine-washing of chicken.

Moreover, the experts warn that because of the UK's lack of negotiating expertise and its desire to sign deals quickly, May will probably have to accept deals as they are if she is to avoid years or decades of wrangling, potentially leaving the UK open to imports below current welfare standards.

"If the narrative is the UK doesn’t want to be subject to 'unaccountable' courts then the UK simply cannot enter into trade deals," Professor Geert van Calster, head of law at the University of Leuven, told BuzzFeed News.

"The very nature of trade deals explains why it’ll be by no means easy, straightforward, and quick to agree a trade deal. The only quick way to a US–UK agreement would be to take TTIP and sign it.

"Now whether that would be possible for the UK I very much doubt. If the UK were worried about the impact of TTIP on the NHS, agriculture, and public health then why would they not be now?"