Here are some of what seem to this writer crucial exchanges during the third day of the Brexit High Court case R (Miller and Santos) v Secretary of State. They concentrate on exchanges between the judges in the case and the lawyers. The original runs to 160 pages. The digested version of the first day is here. And the second day is here. The links to the transcripts appear at the bottom along with quoted cases and comment. (Note, some page numbers are included; they come at the bottom of the relevant pages ie refer to the text above). A report on the Supreme Court case is here: What if Eadie was right?
The third day of this case (Oct 18)
James Eadie QC on how the Article 50 notification process would work. He notes “there will on any view be considerable further Parliamentary involvement in the future” to which the Lord Chief Justice replied “Mm-hm”.
MR EADIE: [I]f there was an Article 50(2) withdrawal agreement, that would be a treaty between the United Kingdom and the EU.
THE LORD CHIEF JUSTICE: Yes.
MR EADIE: As such, it is likely that it will come within the procedures in CRAG [Constitutional Reform and Governance Act 2010]. … It will be a treaty, but I say likely to fall within the procedures within CRAG, because CRAG, like the Ponsonby memorandum which it sought to embody … CRAG only applies to treaties which are subject to a formal process of ratification. See, amongst other things, section 25(3) and (4), and indeed the process of ratification which is the cornerstone of the Act in section 20. Now, almost all treaties are, but not all treaties are, subject to ratification. In other words you can on the international plane enter into an agreement without ratification necessarily following … those agreements do happen but they are pretty rare, and it is considered very likely that this agreement, if entered into, in other words the 50(2) agreement, would be a treaty requiring ratification. Of course one can’t exclude the theoretical possibility that it wouldn’t be.