Blow for Boris Johnson as Arlene Foster rejects fresh customs compromise on Irish backstop
The DUP will never accept a Brexit deal that sees Northern Ireland signed up to different customs rules to the rest of the United Kingdom, Arlene Foster has warned Boris Johnson.
The party's leader said Northern Ireland had to leave the European Union "on the same terms as the rest" of the UK - and warned Mr Johnson not to make the same "mistake" as Theresa May as he searches for a Brexit deal.
Ms Foster said it was still possible for the Prime Minister to reach an agreement with the EU "at this late stage", despite months of wrangling over the so-called backstop plan to avoid a hard border between Northern Ireland and the Republic if talks break down.
But she warned: "We have to leave on the same terms as the rest of the United Kingdom. We can't have a different customs arrangement."
And Ms Foster added: "When we set out our position, that is our position. That is the mistake, unfortunately, that Theresa May made. Our whole raison d'etre is the Union - that is why we go into politics."
The DUP leader's comments come after Downing Street moved to shut down speculation that ministers were considering bringing back a version of the backstop that would see EU customs rules apply only to Northern Ireland.
Such a plan was rejected by Mrs May who said "no British prime minister" could ever accept a regulatory border being created in the Irish Sea.
Ms Foster doubled down in her opposition to that plan at the Conservative fringe event, warning: "We cannot have internal customs borders within the United Kingdom... it has constitutional implications as well as economic implications.
"Actually, when you think of the amount of trade we do East-West and West-East, it completely blows out of the water the North-South trade.
"I'm not saying the North-South trade is not important - it is of course important - but our East-West trade is much more important."
While the DUP leader said her party would "look at" a time-limited version of the backstop, she pointed out that such a plan had long been rejected by European leaders.
"In terms of the time-limited backstop, can I remind you what [Irish Taoiseach] Leo Varadkar thinks of the time-limited backstop - he says it is not a backstop at all," she
"And so in terms of the time-limited backstop we have said in the past it is something we would look at.
"I don't think it is something that Leo Varadkar would look at, but certainly if a time-limited backstop was on offer it is something that we would look at.
"But I don't believe it is at this present moment in time."
The Government has repeatedly called on EU leaders to remove the "undemocratic" backstop plan from the existing EU withdrawal agreement, arguing that the plan would leave the UK bound by Brussels rules indefinitely if it is triggered.
But the EU has argued that the backstop remains the only realistic way to avoid a hard border between Northern Ireland and the Republic, as well as protecting the EU's internal trading system if talks between the two sides run aground.
While a wave of Tory sackings and defections means the DUP no longer provides the Government with a majority in the Commons, Cabinet minister Jacob Rees-Mogg on Sunday predicted that a decision by the Unionist party to back a Brexit deal could get it over the line.
He told activists: "I think if the DUP are happy with the deal there will be very few Conservatives, including those who are without the whip, who are then against a deal.
"And at that point there are a number of people in other parties who think that yes we must now just finish this."