Boris Johnson will travel to Luxembourg on Monday in the latest round of talks between the EU and the UK to find a way that will lead to a Brexit deal. Here’s what he can expect.

Is Boris Johnson closing in on a Brexit deal?

No, but there is at least a sense of where a potential solution might lie – with something that looks a bit like the Northern Ireland-only backstop, rejected by Theresa May and the Democratic Unionist party (DUP).

Boris Johnson has repeatedly mentioned the idea of an all-Ireland zone for agri-foods, citing Ian Paisley’s remark that “our people may be British but our cows are Irish”. That could result in Northern Ireland abiding by EU rules on agriculture, preventing the need for border checks.

But Dublin has pointed out that this only deals with 30% of the challenge, and border checks of some kind would still be necessary if the UK wants to diverge from EU rules and tariffs in other areas. That’s why the Northern Ireland-only backstop, which would mean regulatory alignment with the EU in other areas, is being talked about again.

Speaking earlier this week, Johnson rejected the idea, saying: “I’ve seen a bit of chatter about this, stuff in the media … we will not accept a Northern Ireland-only backstop. That simply doesn’t work for the UK. We’ve got to come out whole and entire and solve the problems of the Northern Irish border, and I’m absolutely certain that we can do that. But we’re working very, very hard, flat out, to do that.”

Q&A What is a Northern Ireland-only backstop? Show The British government’s version of Brexit involves the UK ultimately leaving the single market and customs union, requiring the return of a range of checks on goods crossing the border between Northern Ireland and the Republic of Ireland. The “backstop” is intended as a standstill placeholder to ensure such checks do not have to be imposed between Brexit happening with a deal, and the start of a new free trade agreement yet to be negotiated between the UK and the EU. Theresa May's withdrawal agreement proposed keeping the whole of the UK in a shared customs territory with the EU during this period. An alternative idea involves only Northern Ireland staying in the EU’s customs territory. That would place a customs border in the Irish Sea. May described it as a threat to the constitutional integrity of the UK, but the new prime minister, Boris Johnson, has opened the current talks by proposing an all-Ireland agri-food zone. The suggestion is that he will seek to quietly build on that with further NI-only arrangements. Given an NI-only backstop was an EU proposal in the first place, the U-turn would be warmly welcomed in Brussels, although attempts to give the Northern Ireland assembly a veto on its continuation would not be acceptable, and the DUP would be unlikely to support the prime minister in such a move in parliament. If there is a no-deal Brexit, then there is no backstop. Daniel Boffey

Is the DUP softening on a Northern Ireland-only backstop?

Publicly they continue to insist they are not softening and a Times story on Friday hinting at a shift in the DUP’s thinking was rejected by the DUP’s leader, Arlene Foster, who echoed Johnson’s language, saying the UK must “leave as one nation”.

UK must leave as one nation. We are keen to see a sensible deal but not one that divides the internal market of the UK. We will not support any arrangements that create a barrier to East West trade. Anonymous sources lead to nonsense stories. #frontpages — Arlene Foster (@DUPleader) September 12, 2019

But there is no doubt that the government is putting a lot of effort into finding some combination of regulatory alignment, checks away from the border – at ports and airports – and democratic consent to satisfy all sides.

Why are the Brexiters [still] so exercised about the backstop?

For Johnson and the Vote Leave veterans, with whom he has packed Downing Street, Brexit is only worth doing if the UK can “diverge” from the EU by setting its own rules. That’s why they want a Canada-style, free-trade deal with the EU27, instead of the closer and more complex relationship May was proposing.

While they initially signed off on the December 2017 joint framework that contained the backstop, Johnson, Gove and others came to see it as tying the entire UK into the EU’s regulatory orbit indefinitely. Their test for any new deal will be whether it allows the divergence that they regard as the reason for the whole project in the first place.

But that will be exceedingly difficult to reconcile with the DUP’s insistence that there must be no barriers for businesses in Northern Ireland accessing markets in the rest of the UK.

Could Johnson just cut the DUP adrift?

Theresa May patched together a majority in the aftermath of the 2017 general election by striking a confidence-and-supply agreement with the DUP – helped by an extra £1bn in public funding for Northern Ireland.

There is an argument doing the rounds in Westminster that since Johnson now has no majority anyway, as has been clearly shown by a string of Commons defeats, and with the confidence-and-supply arrangement up for renewal before the Queen’s speech next month, 10 MPs either way will not make a difference.

But the numbers in the Commons still look extremely tight for Johnson if he does bring an agreement back next month. And the DUP’s approval would be a strong signal to the Spartans – the most ardent Brexiters who rejected May’s deal three times – that a deal was acceptable.