Brexit: How are the UK's talks with the EU going?
Despite predictions that talks on a Brexit deal are on the brink of collapse, they struggle on.
There is, however, a limit to what technical discussions in Brussels can achieve.
This is about politics now – and time to get anything done and dusted by the end of the month has all but run out.
After a meeting between Boris Johnson and the Irish PM Leo Varadkar, a joint statement said the two men could still "see a pathway to a possible deal". But they highlighted two major challenges: customs and consent.
So, where have we got to?
The UK wants to rewrite the Protocol on Ireland and Northern Ireland that forms part of the proposed withdrawal agreement – the terms of divorce negotiated by the EU and the UK government under Theresa May.
First and foremost, the UK now insists the backstop – the legal guarantee to avoid the return of a hard border in Ireland – has to go.
The UK plan to replace it would leave Northern Ireland inside the EU single market for all agricultural and industrial goods but outside the EU customs union.
In effect that means a "light-touch" north-south border for customs (between Ireland and Northern Ireland) and an east-west border for regulations on goods (between Great Britain and Northern Ireland).
Many businesses in Northern Ireland have already criticised the UK proposal as the worst of both worlds.
And the EU says it sympathises with companies on both sides of the Irish border that would suddenly face a far more complex and costly business environment to operate in.
But it still takes a more nuanced view, because it wants a deal done and doesn't want to be blamed if the whole process collapses in acrimony.
EU negotiators also appreciate the fact the UK has moved on the issue of regulations and has now proposed setting up a single zone, following EU rules, on the island of Ireland. That means checks on goods – especially food and agricultural produce – would have to take place within the UK (between Britain and Northern Ireland) instead.
But the EU has identified several other sticking points and concluded the UK proposal as currently drafted cannot form the basis for an overall deal.
What about customs?
This is the biggest problem.
The UK wants customs checks to take place away from the Irish land border, using technology, exemptions for small businesses and trusted trader schemes.
But that means it wants the EU to agree in advance, as part of a formal treaty commitment, there will never be any customs checks at the border itself, even before the EU knows exactly how the UK's customs proposals are going to work.
The EU isn't willing to do that.
It would also mean an international agreement known as the Common Transit Convention (CTC) would have to be renegotiated to avoid the need for documents to be checked at or near the border.
And it would mean the EU would have to make special dispensations for the UK in Northern Ireland, exempting it from some of the customs rules set down in EU law. This, the EU believes, would threaten the integrity of its own economic structures – the customs union and the single market.
The UK is urging the EU to think more creatively. But overall, the EU still doesn't see how the Irish border can remain as open as it is now – certainly in the short and medium term – if Northern Ireland is no longer in the same customs territory.
And it argues the UK plan relies on technology not yet deployed at any other border in the world.
What about consent?
This is the other big problem.
The UK says Northern Ireland cannot be expected to accept rules and regulations over which it has no say, without first giving its consent.
But the method it proposes to gain that consent would – in effect – give one party, its allies in the Democratic Unionist Party (DUP), a veto over whether to create an all-Ireland regulation zone, and then another veto every four years on whether such a zone should remain in place.
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It's not clear whether the issue of consent could also extend in the future to any new customs rules – but the basis of the Good Friday Agreement that helped to bring peace to Northern Ireland was no single party could wield a veto over any aspect of the deal.
So, if a method could be found to seek the regular consent of all parties in Ireland, for post-Brexit trading arrangements, that could provide a way forward.
Although neither side would seek to call it this, it would be a form of time-limited backstop.
What about the rest of the withdrawal agreement?
The rest of the withdrawal agreement negotiated by the EU and Theresa May's government – including the financial settlement and the transition period, things heavily criticised in the past by Boris Johnson – would remain in place.
So, even if a last-minute deal could be done – which looks unlikely before the end of October – the prime minister would have to accept parts of an agreement he has rejected in the past.
The next few days are obviously critical.
Neither side wants to be seen as the one to walk away from a process of talks, not least because they know at some stage they would need to start talking again.
Sometimes in complex negotiations deals emerge at the 11th hour in the most unexpected of places.
"I think the deal is possible," the EU's chief negotiator Michel Barnier has said, "very difficult but possible."
But politics on all sides, and particularly in the UK, seems to have brought this process very close to an impasse.
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