The DUP and ERG seem to be building an argument that if Northern Ireland is still bound by EU regulations on goods, this stops the rest of the UK diverging from EU rules, and as a result the full benefits of Brexit can't be exploited. Johnson seems to have decided to hop on board. Expect to hear lots about divergence over the next couple of weeks. I don't really understand the argument. Are they saying that if the rest of the UK can produce goods to a lower standard, they will be cheaper and they will be able to export more to other countries? But then they won't be able to export the goods to the EU. It seems pretty complicated.