Thread by @pmdfoster

EXC: If @BorisJohnson wants to make good on his threat to withhold £39bn #Brexit bill he will need to over-turn existing legal advice from AG Geoffrey Cox - who supports him. Could be awkward. 1/Thread

@BorisJohnson Just to recap, Boris opened his campaign with a big promise to re-open the linkage between the #Brexit bill and outcome in the future relationship - which @DavidDavisMP one said would be the 'row of the summer' (that lasted a day) /2

@BorisJohnson @DavidDavisMP The Boris intervention surprised some of my regular contacts in Brussels.

They felt that Boris might work up to that level of 'threat' as the rhetoric of the leadership campaign escalated.

But no, he went in two-footed, studs-up from the outset. That rattled a few cages. /3

But can Boris make good on that promise to withhold the Brexit bill and use it as leverage to get better outcomes?

Brexiteers get very hot under the collar about this, but the legal advice - per my sources - is, ahem, unhelpful. /4

There are two scenarios in which the UK might not pay the Bill - or rather might link payments to progress.

1) a 'no deal'

2) after a deal, but before the future relationship negotiation is complete.

Let's take each in turn. /5

I've done a detailed piece on the bill issue, but the short version in a 'no deal' is that UK has already admitted that it has "survivable obligations" from it's EU membership. /6

telegraph.co.uk/politics/2019/…

True, the size of those obligations IS contested (UK officials say the deal never conceded @michelbarnier point that what was agreed at 28 must be paid for at 28)...

....but the reality is that in a 'no deal' the battle over the money is going to be a political not legal fight/7

@MichelBarnier The EU made very clear back in February (as the March 29 deadline approached) that any kind of non-catastrophic 'no deal' will require payments.

Brexiteers talk about a 'managed' no deal? Payments.

The EU budget @GOettingerEU made same point again last week /8

@MichelBarnier @GOettingerEU But what about the second scenario - linking progress in trade talks to bill payments.

Now THIS is more interesting, since it seems if you read @BorisForeignSec quote carefully, what he's driving at.

"Retain"...until there is "greater clarity". /9

@MichelBarnier @GOettingerEU @BorisForeignSec This could be VERY material, since presumably part of the @BorisJohnson pitch, given the limits of what can be achieved in renegotiating the political declaration, is going to be a promise to "tackle hard in the second half" - this was his justification for voting for MV3 /10

@MichelBarnier @GOettingerEU @BorisForeignSec @BorisJohnson Now...if Boris was to a promise to withhold payments on the Bill as a way of putting meat on the bones of that promise to "tackle hard" - viz "we won't give them a red cent until they take our need for 'alternative arrangements' on the Irish border seriously" - we have a prob/11

@MichelBarnier @GOettingerEU @BorisForeignSec @BorisJohnson My sources say that in November 2018 @DominicRaab - when he was Brexit secretary - wanted to put just such a 'rider' on the Withdrawal Agreement Bill - but the attorney-general said "no", because that would be illegal. /12

@MichelBarnier @GOettingerEU @BorisForeignSec @BorisJohnson @DominicRaab I have not seen the advice, but I understand that it is on-record in the system.

Geoffrey Cox was very clear that Article 18 of the Vienna Convention on the law of treaties which says that states that sign treaties can't take steps which would frustrate said treaty. /13

@MichelBarnier @GOettingerEU @BorisForeignSec @BorisJohnson @DominicRaab Now, I'll leave m'learned friends on Twitter @CSBarnard24 @StevePeers and others to weigh in here on the legals...but politically, given Mr Cox is supporting Boris, this presents and interesting political scenario too. /14

@MichelBarnier @GOettingerEU @BorisForeignSec @BorisJohnson @DominicRaab @CSBarnard24 @StevePeers Because I think Boris, if he is going to 'sell' a compromise (including perhaps committing to Canada-style FTA as the stated, desired outcome in the revised Political Declaration) is going to have to play the "tackle hard in the second half" line hard. /15

@MichelBarnier @GOettingerEU @BorisForeignSec @BorisJohnson @DominicRaab @CSBarnard24 @StevePeers It seems clear, talking to my sources on both sides of the Channel, that - both legally and politically - that is playing with fire. ENDS/16