Interesting background about what happened to start the latest talks:
Brexit breakthrough: Injury time winner, or fatal gambit?
https://www.rte.ie/news/brexit/2019/1011/1082783-brexit-connolly/
the breakthrough was not anticipated and had pierced the mood of gloom that had settled over Brussels.
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On Tuesday night Simon Coveney made an eyebrow raising dash to Brussels to meet Mr Barnier, having been involved in a budget-related news conference as late as 4.30pm.
If an idea was going to be hatched in Dublin it would have to be cleared through the Task Force first, to avoid the perception that Ireland was negotiating bilaterally with the UK.
"It was all sychronised with the EU and the Task Force," says a senior EU figure on Thursday night after the Johnson-Varadkar meeting.
....
He [Barnier] rejected the idea that he was recommending a "tunnel", the secretive, leak-free process which heralded the final breakthrough in the initial Withdrawal Agreement negotiations one year ago.
Instead, he suggested that the new proposals were simply worthy of exploration.
"The Commission wanted to see how far it was possible to go," said one source close to the negotiations, "and then we’ll see".
However, Barnier delivered two key messages:
the UK had moved on customs and had moved on consent, the two most difficult aspects of the British proposals.
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However, it will be politically perilous for Mr Johnson, not least because he resigned as foreign secretary over a similar plan for the whole of the UK.
If the DUP rejects it, the European Research Group may follow suit, and Mr Johnson might need the support of up to 70 Labour MPs.