Thread by @tconnellyRTE

Here goes:
Barnier's offer on Fri that "best endeavours" could be actionable by the UK at independent arbitration level appears to have unblocked things. ie, the offer of a Joint Interpretative Statement which commits both sides to best endeavours/good faith + is legally binding

So you have the beefed up "best endeavours" part - to remind people, that's about the UK's demand that the EU is acting in good faith to replace the backstop with a fully fledged FTA / alternative arrangements / technology etc...

Then, as I understand it, you will have language tonight on how the Independent Arbitration panel can use the best endeavours clause as evidence to support a future UK complaint that the EU is not acting in good faith etc.

The third, and trickiest part, is a Unilateral Declaration by the UK.

This is complex, so bear with me.
As I understand it, the UK wants to declare that it will be able to walk away if the trade talks are dragging on, the transition runs out + the backstop is upon us, and it's not true to its purpose because it's not meant to be permanent etc etc

This is the nub of the difficulty in tonight's talks. The idea of a unilateral interpretation of the backstop. If the UK invokes it, obviously at that point the EU will put forward a counter argument that the backstop is needed PRECISELY because the trade talks are stuck etc

The UK's capacity to have a unilateral interpretation could, however, be nodded through tonight as a principle the EU can concede, but if the reasons for the UK walking away cut across the WA, then all sorts of EU red flags will go up...

The EU would insist then on the issue going to the arbitration panel. But that would no longer make it a "unilateral interpretation", which is, of course, the conundrum.

The EU, meanwhile, sees the issue in three ways: 1. It's precisely because the talks break down that you need the backstop 2. The issue is intensely political: what if Corbyn is PM, and he goes for a customs union so part of the reason for the backstop falls away?

3. The UK has a shared responsibility to make this work.

This is my understanding of the issues under discussion. Obviously the Irish side have been briefed, hence the cabinet meeting earlier. I'll file more stuff as I get it.