Tánaiste Simon Coveney has admitted it will be "very, very difficult" to avoid physical infrastructure on the Irish border if there is a no deal Brexit as the Government published its doomsday Brexit plans.
Mr Coveney said while the Government is still "intending" to prevent a hard border and has no secret plans in place, the situation will become "much, much more complicated" if Britain crashes out in just 100 days time.
"If we don't get that deal, well then preventing border infrastructure is still something we are intending to do, but it becomes much much more complicated.
"That doesn't mean we're not absolutely committed to avoiding border infrastructure, but it becomes a very very difficult thing to get right in the absence of the deal that has already been agreed and is on the table.
"There are no easy answers to that, that's the truth," Mr Coveney said.
The Tánaiste was speaking as the Government published its 100-page no deal Brexit contingency plans with just 100 days to go until the March 29, 2019, Brexit divorce deal.
However, assurances have been given that the common travel area between Ireland and Britain is safe as it "pre-dates" EU membership, while officials have stressed no food shortages will take place.
Mr Coveney described the "damage limitation" plans as "sobering" and said the Government document shows that "anybody who belittles the consequences of a no deal Brexit suggesting this is another millenium bug that isn't going to have any real impact, really doesn't know what their talking about".
"The consequences of Britain leaving without a comprehensive deal ... will be very damaging. It will certainly put the country under a lot of strain in the first half of next year," he said.
Mr Coveney was speaking as the European Commission published its own no deal Brexit plans, and as British Prime Minister Theresa May told her cabinet on Tuesday 3,500 soldiers may be needed to cope with domestic unrest in a no deal crisis.
The full 100-page Government no deal Brexit plan can be read here: