Crown Dependencies and the UK
The link is to a court of appeal judgment about Sark which has relevance to the case in Jersey.
This has the helpful part from the MoJ
18. In his witness statement, Mr P.F.U. Bourke, head of the European and International Division of the Ministry of Justice, stated, at paragraph 35:
"Proper consideration is given to the Crown's responsibilities, so that if a Projet de Loi violated the Crown's international obligations or any fundamental constitutional principle, or if it would clearly not be in the public interest for it to become law, then a recommendation might be made to withhold Royal Assent . . .".
19. Mr Bourke described the constitutional position, as he saw it:
"The United Kingdom Government is responsible, as a matter of international law, for any breach by Sark of its international obligations, including its obligations under the European Convention on Human Rights. . . . In addition, the Crown has ultimate responsibility for the good government of the Channel Islands. In this respect, the Crown acts through the Third [Respondent] on the recommendation of Her Majesty's Ministers, in their capacity as Privy Counsellors (ie members of the Third Respondent). In practice, the Third [Respondent's] functions in relation to the Islands principally concern the ratification of legislative measures by way of Orders in Council . . ."