If EU ministers reach agreement only in a political sense at EUCO Thurs/Fri that a Brexit deal with @BorisJohnson is on or do-able, though subject to final legal drafting, then the PM will have to try and repeal the Benn Act during parliament's emergency sitting on Saturday...
since otherwise he would have to ask for a Brexit delay - which he says he will never do (or at least not coerced by the Benn Act). And if a legal agreement is reached at EUCO then MPs will have to approve it in a meaningful vote on Saturday, to render the Benn Act null and
void. The obstacle to either a political deal or full deal with the EU's 27 leaders is their requirement that any customs proposal must be "legally operable", that there must be no room for doubt about whether the border on the island of Ireland will be kept open forever. That...
is why they still want Johnson to agree an NI-only backstop, just in case his dual tariff plan can't be implemented by the time the whole of the UK is out of the EU's customs union and single market (end of 2021 at the latest). Right now EU negotiators hope Johnson will...
drop his principled opposition to any form of backstop and Johnson hopes the EU will drop their principled insistence on the legal operability of any deal. This is the crux, the pinchpoint, the nub - which will determine whether a Brexit deal can be done tomorrow, or at all.
