There was no triumphalism in Theresa May and Jean-Claude Juncker’s press conference. Nor was there much detail. May talked about how the joint interpretative instrument meant that the backstop could be challenged and taken to arbitration if the EU was trying to apply ‘the backstop indefinitely’.
What May did not mention was how this arbitration mechanism would work. Multiple Cabinet Ministers think, after discussion tonight, that the arbitration does not refer to the ECJ. If that is the case, it will convince a slug of Tory MPs that this arbitration mechanism has teeth.
The second aspect is the aspiration to have alternative arrangements in place by the end of December 2020, in other words at the end of the transition. Then, there is the UK’s unilateral declaration—which you can read here.
There are two key questions about this. Is this enough to allow Geoffrey Cox to significantly change his legal advice? If Cox feels he can change his legal advice, then the test is what does Nigel Dodds make of it? The DUP’s Westminster leader is absolutely crucial to all this. If he is happy, then there’ll be huge pressure on the ERG to back the deal—and three leading members of it have already told me that the DUP’s approval would be enough for them.
These changes are not as clear cut as either a time limit or a unilateral exit mechanism. But the issue now is whether there is enough of an appetite in parliament for a deal, for them to be sufficient.