Michael, if the UK enters into a trade agreement with another country they will agree to abide by certain rules and regulations set out within the trade agreement. An arrangement will be agreed within the agreement to deal with any disputes that arise relating to that trade agreement and its rules. They may agree that disputes are initially referred to either country’s legal systems but ultimately there will also be a final court or arbitation panel to which parties in a dispute can appeal, one which is outside of and has supremacy over either country’s legal system (only in relation to the trade agreement) and which will rule on any final binding decision. There is no getting away from some loss of “sovereignty” in such agreements. Every trade agreement the UK makes with any other country will be the same. How is that different from the EU?
If I recall correctly, the TTIP, which Trump scuttled by withdrawing the USA from it had provisions for such non-public extra-national courts of arbitration. At least the CJEU is public.
In the case of the Polish mine you cited, how would such a dispute have been settled in the past? Are so vehemently anti-EU Michael that you don’t or won’t see any reasonableness in the mechanism for arbitrating a dispute such as this one? Remember that all three parties involved agreed to this set-up in a formal treaty. Don’t you think the there is a lot of unreasonable anti-EU bias in the daily express report you cited? I read the report you linked!