Boris Johnson is right about one thing over Brexit – and one thing only

The prime minister has got himself into an international legal hole entirely of his own making – but he is not wholly in the wrong, writes John Rentoul

Boris Johnson has faced a difficult week (EPA)

The prime minister has made a terrible mess of Brexit, and hopes that if there is a big enough fuss about his breaking international law, his Leave voters will rally to him. I suspect that he’s not sure how he’s going to get out of this one, but thinks he’ll be able to find a way, as long as he has public opinion behind him.  

Boris Johnson got into this trouble because he was desperate to do a deal last year. He needed a new EU withdrawal agreement to replace the one negotiated by Theresa May that parliament rejected. He managed to get one, but there was a price to be paid: he had to sign up to border checks between Northern Ireland and the rest of the UK.  

He presumably thought he could sort out the details later. His priority was to agree a text that he could get through parliament. He succeeded. It involved talking quite fast when he was asked about some of the brain-bending technicalities of the “border in the Irish Sea” and changing the subject.