The President of the European Council didn't mince his words on Wednesday, saying there was a "special place in Hell" for people who "promoted Brexit" without a plan.

In an indication of just how strained negotiations between the European Union and the United Kingdom have become, Donald Tusk tweeted that: “I've been wondering what that special place in hell looks like, for those who promoted #Brexit, without even a sketch of a plan how to carry it out safely.”

His comments come as UK Prime Minister Theresa May travelled to Northern Ireland on a mission to seek a way forward on the Irish backstop and salvage her withdrawal agreement that has come under fire from all sides of Westminster.

Meanwhile, Tusk, who is meeting Irish Prime Minister Leo Varadkar in Brussels, stressed again that the withdrawal agreement is not open for renegotiation. “Today our most important task is to prevent a no-deal scenario,” he said.

“I hope tomorrow we will hear from PM May a realistic suggestion for how to end the impasse, in which the orderly withdrawal from the EU has found itself in the House of Commons.”

Last month British lawmakers voted to send May back to Brussels to renegotiate the terms of the Brexit deal over concerns regarding the Irish border backstop.