[Sephiroth]

Originally Posted by nomadking

Nothing contradictory about it. An agreement HASN'T yet been made, with little over 3 months to go. No agreed solution = not allowed. EG if you need permission from somebody else to get access to somewhere, and they don't give it, you don't have access. NI is ALSO part of the UK single market.

So what is this "what" that has been agreed? Any "how" is part of the "what", and would still be something we had to ask the EU permission about.
There are no existing EU rules to deal with the situation of movement of goods from GB to NI, other than a hard border and tariffs.

Nomad has made an important assessment.

The bit that I have italicised is the sticking point. Unless there is formal agreement to the effect that we must ask permission of the EU to do something, that simply must not happen in relation to the UK internal market.