Former taoiseach Bertie Ahern has warned that Brexit poses dangers for the peace process.
"[UK prime minister Theresa] May seems to be switching her language," he told the Observer. "She's saying not that there'll be no Border, but that the Border won't be as difficult as to create problems.
“I worry far more about what’s going to happen with that. It will take away the calming effects [of an open Border]. Any attempt to try to start putting down border posts, or to man [it] in a physical sense as used to be the case, would be very hard to maintain, and would create a lot of bad feeling.”
The former Fianna Fáil leader was also doubtful that modern technology could effectively police the Border.
“I haven’t found anyone who can tell me what technology can actually manage this,” Ahern said, adding: “Any kind of physical Border, in any shape, is bad for the peace process.
“It psychologically feeds badly into the nationalist communities. People have said that this could have the same impact on the nationalist community as the seismic shock of the 1985 Anglo-Irish agreement on unionists, and I agree with that.”