I think what the world needs right now is 4 slides putting the #Brexit border issue as simply as possible. So here goes...

Here is a very simple outline of what border controls mean for different types of border with the EU, i.e. if in the EEA, if in a Customs Union, with a FTA, with nowt. The spectrum is vast. This is just the basics, with a focus on goods.

This, again, is a simple outline of what a customs border requires, both for those moving goods across it and for those charged with enforcing it. It is intended to show that a 'hard border' is not just determined by its visibility. And this is before we even touch on NTBs etc.

Here we have a very basic outline of what 'smart border technology' can do and what it requires. It is primarily a means of enhancing efficiency. It cannot make a hard border 'frictionless'. It requires physical infrastructure. It does not obviate the need for inspections etc

And here are, as I see it, the main scenarios we are looking at for UK/EU borders post-Brexit + a summary of what each would mean for GB/NI & NI/IRL borders. IMO the draft Protocol is narrow interpretation of Joint Report. UK in a CU wd be minimum to keep E/W open as possible.

@hayward_katy Thanks Katy - really clear and helpful. Any sense of why the Revenue is downplaying the need for physical infrastructure?

@EamonCassidy4 Because they interpret no hard border to mean an invisible border. The Joint Report went even further in saying no physical infrastructure and no checks or controls! Which means no customs border, it can't mean anything else. Hence draft Protocol having NI in EU customs territory

@hayward_katy What effect, if any, do you think the new wto Trade Facilitation Agreement would have?

@EFTA4UK To be honest, I don't know the answer to that.

@hayward_katy You imply no movement of people etc across ROI/NI border, but is that correct? Before 1973 we had substantial free movement, indeed ROI and UK citizens had something other EU don't have, right to vote in other's national elections. Are we not being told that aspect will remain?

@Onebiskuit This is about trade rather than immigration. CTA doesn't have any effect on the movement of goods. Indeed, the customs border along the Irish border existed long after CTA was created. It was only made redundant through EU integration.

@hayward_katy Many thanks for this. What stands out is that Agricultural goods, the main part of our economy is particularly vulnerable in all circumstances.

@MartinG1492 Yes, it's an absolute must in terms of 'bespoke' arrangements for NI/IRL. Ideally it would be included in UK-EU FTA too, especially given UK-IRL trade in this area. But that is very ambitious and would require careful, detailed negotiation. Which would need time and goodwill...

@hayward_katy @threadreaderapp unroll

@hayward_katy Thanks for this. Personally I keep getting stuck on the presumption(?) that the existing #EU ways of doing things are unchangeable. Thinking out of the box, and knowing that the #EU is a legalistic entity, what could be achieved if the #EU27 had a political will?

@hayward_katy Most intelligent thread I've read on the Border complexity yet! Thank you

@hayward_katy Really useful, thank you.

@hayward_katy Brilliant. It comes back to any change is difficult and will take time whatever politicians like to believe.

@hayward_katy Excellent posts. I think you have brilliantly set out what I worked out. Including that numberplate recognition doesn't show who are the passengers or where the dead chickens in the lorry came from. Nor that the electrical goods legal in "Free England" are CE standards.

@hayward_katy This explains why @DavidDavisMP 's original fantasy customs and border proposals were an insult to his EU counterparts and a means of deceiving parliament and the British people.

@hayward_katy One question on the last slide. Why do you differentiate between the NI/ROI border and the GB/EU? Is it not the same thing as ROI is part of EU?

@hayward_katy @KateHoeyMP please take on board

@hayward_katy Funny, because the EU chose to do nothing about mass migration, so arguments about how they need to tightly manage borders are somewhat hollow.. Ask the Greeks and Italians...

@hayward_katy Thanks a million Katy. This is really helpful and clear. Even my Leaving Cert politics and Society students should be able to get their head around this!

@hayward_katy Thank you, perhaps you should send a copy to @DavidDavisMP and his “colleagues”.