Judge Carnwath says he's a critic of concept of sliding scales.
Wollfe says separation of powers is "predicated on accountability of government to parliament". Court must grip what happens if this is removed.
GFA was "premised on continuing EU membership", as it cites "the close co-operation between their countries as friendly neighbours and as partners in the European Union".
Lady Hale comes in firmly.
"We’re not concerned with any of that. We’re concerned with the lawfulness of the PM’s decision.. We’re not concerned with when, how and on what term the UK leaves the EU."
Judges v unhappy: “What does that have anything to do with the prorogation of parliament?”
"not a question for us"
"Completely irrelevant"
"the purpose of this hearing is not to rehearse the pros and cons of Brexit.”
"I am really worried about your submissions. People are listening to your submissions: they will hear these points about Brexit and NI and will come to entirely the wrong conclusion. Don’t abuse our politeness and don’t abuse Lady Hale’s patience."
Context is Court is acutely sensitive to the charge that it is taking a "political" view on Brexit more broadly.
Lady Hale: “We never, ever mind if people take less time than they have intended for.”
It's about the "broader" idea of "dynamism of ongoing legislative autonomy"... protecting what parliament wants to do tomorrow
This has included Dominic Cummings, he adds.
That's wrong, but “The fact that the allegation was made suggests it was an impermissible use of the power" and undermines HMG, he says.
“It would be a strange constitution that protected against a conscientious executive but not against a reckless one.”
“We don’t buy the argument that the woman who wrote the article had a different character or mental state than the one who wrote the briefing paper.”
“They are inviting the courts into forbidden territory and an ill-defined minefield."
Judge Reed: That sounds like something which ought to go without saying.
Keen: It’s not for the executive to give undertakings to obey the law. The executive does obey the law. If the court tells us what the law is we will address that
But nonetheless, the PM did have improper purpose. The govt has failed to answer the PM's own TV interviews or provide a witness statement.
Pannick is turning this on its head: Recall parliament, then let them decide, and dont get involved any further.