The 9th July “JHA opt in decision” is that even if the proposed EU regulation on the law applicable to so-called “third party effects” became law, the UK would not adopt it. Constitutional scholars will already know that the EU’s power to make the Regulation stems from Article 81(2) of the Treaty on the Functioning of the European Union, and since it concerns “Justice and Home Affairs”, the UK has power not to opt in. The default position it proposed where you have two competing assignments is that the law of the assignor’s habitual residence should govern priority, because that is probably where the main insolvency proceedings would, subject to exclusions for bank deposits, claims derived from financial instruments, and securitisations (where parties can choose the law of either the assignor or the assigned claim), and assignments of claims relating to trusts. The May 2018 CLLS paper called this “misconceived”, and argued any default position should be determined by the law of the claim, and the UK government has seemingly been persuaded.