Northern Ireland First Minister Arlene Foster has said she will not tolerate passport controls between Northern Ireland and the UK.
Former British prime minister David Cameron had raised the possibility of passport checks at Scottish ferry terminals which would have meant people not being able to travel freely between Northern Ireland and Britain.
In an interview with the News Letter Ms Forster said she had received assurances this would not happen.
"We've been very clear with the Prime Minister (Theresa May) and the Secretary of State (James Brokenshire) that that is a red line for us; that there cannot be any internal borders within the United Kingdom. That has not only been acknowledged, but accepted."
On Saturday Ms foster is giving her first keynote speech to her party conference as First Minister and DUP leader.
Ahead of the conference Ms Foster said she does not like the way Taoiseach Enda Kenny – she feels – tried to bounce her into supporting his all-island civic forum on Brexit.
Recalling how Mr Kenny had made his proposal – just before a North South Ministerial Council meeting in Dublin, in July – Ms Foster said: "It was very badly mishandled. We weren't aware of his decision to set this forum up until I arrived in Dublin. I made it very clear that I was not going to be a part of it."
