DUP leader Arlene Foster has issued a stern warning to politicians in Brussels and Dublin over using the issue of the Northern Irish border to "blackmail" the UK in the Brexit talks.
The former First Minister accused leaders of "recklessly trying to use Northern Ireland for their own objectives" just days after Taoiseach Leo Varadkar said Dublin would try to block EU trade talks unless it received a guarantee there would be no hard border on the island of Ireland.
The Irish border has become one of the key issues for Brexit negotiators amid concern that any changes to the constitutional position could undermine the peace process.
In a strongly-worded statement ahead of talks in London, Ms Foster said it was "downright careless" to suggest leaving the EU would cause a return to violence not seen since the Troubles.
It comes as Theresa May was due to meet Northern Ireland's leaders at Downing Street over the ongoing power-sharing crisis at Stormont, which has been without a functioning administration since January.
Speaking ahead of the talks, Ms Foster said: “The people of Northern Ireland delivered peace and stability. Yes, they were supported beyond these shores but to suggest that exiting the EU will bring violence onto our streets is downright careless.
"Northern Ireland will exit the EU on the same terms as the rest of the United Kingdom. We will not countenance a border in the Irish Sea.
"I welcome the Prime Minister’s commitment on this point. The GB market is not only critical for Northern Ireland but for the Republic of Ireland.
"We want to see a sensible arrangement that can work for all concerned. The democratic wishes of the British people must be implemented.
"Those in Dublin and Brussels, recklessly trying to use Northern Ireland for their own objectives, should cease. The Prime Minister should warn Brussels that Northern Ireland must not be used as blackmail.”
Brussels' chief Brexit negotiator Michel Barnier suggested Northern Ireland could opt to stay in the customs union after Brexit in an attempt to kick-start stalled talks, but the move goes against Ms May's promise to take the UK out of the EU institutions.
The Prime Minister will meet Ms Foster and her deputy Nigel Dodds today to discuss restoration of power-sharing before holding separate talks with Sinn Fein president Gerry Adams.
The institutions collapsed when the late Martin McGuinness stood down as deputy first minister following a row about a botched green energy scheme, which ended the power-sharing agreement between the two parties.
The dispute has laid bare deeper issues between Sinn Fein and the DUP, and several Government-set deadlines to form an administration have passed without success.
Northern Ireland Secretary James Brokenshire intervened earlier this month to set a budget for cash-strapped public services.