The leader of the DUP is expected to use a meeting with business leaders in Dublin to address claims that the party is preparing to soften its position on the backstop.
Arlene Foster is scheduled to attend a business conference in Dublin this week.
The party has spent much of the past week countering claims that it is prepared to accept a Northern Ireland only backstop to help the UK government reach an agreement with the EU.
Speculation about such a move increased after British Prime Minister Boris Johnson accepted a need for "alignment" with some EU rules in Northern Ireland.
Speaking during his trip to Dublin last Monday, he said it was possible to "protect the economic unity on the island of Ireland".
The Times newspaper later reported that "DUP sources" had signalled the party was preparing to shift its position.
But senior party members have publicly insisted that a Northern Ireland only backstop is unacceptable as it would be undemocratic.
In a tweet, Arlene Foster said: "UK must leave as one nation. We are keen to see a sensible deal but not one that divides the internal market of the UK."
Writing in the Sunday Independent today, the DUP's chief whip Jeffrey Donaldson said he believes a deal can be done that allows the UK to leave the EU while maintaining an open border in Ireland.
Outlining the DUP’s opposition to the mooted alternative backstop proposal, he said it would keep Northern Ireland effectively inside the EU’s customs union and single market and create barriers to trade with the rest of the UK.
Arlene Foster will use a speech at the business event in Dublin to put the record straight.
She is expected to spell out precisely what the DUP will, and won’t, accept in any Brexit agreement.
There are no plans at this stage for any political meetings during the visit.