The Northern Irish party which props up Prime Minister Theresa May says it will not accept any Brexit deal that sees Northern Ireland diverging either economically or politically from the United Kingdom.
"We will not allow any settlement to be agreed which causes the divergence politically or economically of Northern Ireland from the rest of the United Kingdom," said Nigel Dodds, the deputy leader of the Democratic Unionist Party (DUP).
"There is now an agreement that the United Kingdom stands together and nothing will happen that will cause the breakup of this great United Kingdom," he went on.
Brexit minister David Davis said Dodds was right.
Davis also said the issue of a frictionless border between the UK and Ireland was best dealt with in the next phase of Brexit talks.