DUP threatens to pull support for Theresa May's Government over special Northern Ireland deal
Arlene Foster has threatened to pull out of a deal to prop up Theresa May's Government if it adopts a Brexit deal that treats Northern Ireland differently from the rest of the UK.
The Democratic Unionist Party (DUP) leader warned that customs parity with Britain was a "red line" for her party, whose ten MPs support the Conservatives in Westminster under a "supply and demand" arrangement.
UK Cabinet ministers are currently examining ideas to solve the Irish border issue after Britain quits the European Union.
One idea reportedly proposed by Brexit Secretary David Davis - and dismissed by Downing Street - would see Northern Ireland covered by a joint regime of UK and EU customs regulations, allowing it to trade freely with both, plus a 10-mile wide "special economic zone" on the border with Ireland.
But Ms Foster told Sky News: "For us, our only red line is that we are not treated any different from the rest of the United Kingdom, that there are no trade barriers put up between Northern Ireland and our biggest market which, of course, is Great Britain.
"That's what we will judge all of the propositions that are brought forward, we will judge it against that red line and she's very much aware of that, and I have confidence that she knows that she cannot bring forward anything that will breach that red line or we simply will not be able to support them."
UK Cabinet ministers were last month tasked with analysing the two main options so far put forward for the Irish border, a "customs partnership" proposal that would see Britain continue to collect tariffs on behalf of the EU and the technology-based "maximum facilitation" - or "max fac" - solution. Mr Davis' idea was dubbed "max fac 2".
Brussels has already rejected both schemes, with chief Brexit negotiator Michel Barnier saying on Friday that neither was "operational or acceptable".
EU leaders including Taoiseach Leo Varadkar have called for progress by the time the European Council meets at the end of June, with Tanaiste Simon Coveney on Saturday also telling the Irish Times the UK must produce "written proposals" for the border within the next two weeks.
Ministers on Sunday moved to dismiss reports that civil servants have been drawing up scenarios for a "Doomsday Brexit" that would leave the country short of medicine, fuel and food.
The Sunday Times said models for mild, severe and "Armageddon" reactions to no-deal exits were created, with a source saying that even the severe scenario saw the Port of Dover "collapse on day one".
Home Secretary Sajid Javid told the BBC's Andrew Marr Show: "I have to say I don't recognise any bit of that at all and as Home Secretary .. I am deeply involved in 'no deal preparations' as much as I am in getting a deal - I'm confident we will get a deal.
"From the work that I have seen and the analysis that has been done, those outcomes ... I don't think any of them would come to pass."
He added that the Government was making progress with Brexit plans, saying: "I'm confident that as we get to the June council meeting the Prime Minister will have a good set of proposals and our colleagues in Europe will respond positively."
Shadow international trade secretary Barry Gardiner said the Government's refusal to remain in a customs union with the European Union would ensure the UK was a "minnow trying to compete against whales" on the global stage.
He told Sky News Labour's Brexit policy would ensure "trade in goods would continue uninterrupted", adding: "The Tories' red line is actually going to make it much, much more difficult.
"They're the ones who will be isolated, they will be minnows trying to compete against whales.
"They will be a 70 million strong consumer market against America's 500 million."