A no-deal Brexit has been labelled an "ugly prospect" by the Minister for Foreign Affairs, Simon Coveney.
The Government has unveiled its latest plans to deal with the UK crashing out of the EU in October.
Customs checks will be needed somewhere in Ireland if there is a no-deal Brexit.
The Government’s latest contingency plan concedes checks will be needed on goods and livestock coming from north to south if the UK crashes out without a deal.
However, the Government insists that does not have to happen at the border and it is not planning for a return to customs posts.
Discussions with the European Commission are continuing over the issue in order to protect Ireland's place in the single market.
Tánaiste Simon Coveney insists the Government will prevent physical infrastructure on the border.
However, he has warned a no-deal Brexit will be disruptive.
Mr Coveney said: "A no-deal Brexit is an ugly prospect. It will put many businesses and many people under a great deal of strain.
"It will put political relationships on this island under a great deal of strain, in my view. It will make it more difficult for the institutions of the Good Friday Agreement to function and it will be a fundamental disrupter to the all-island economy."
Cabinet ministers are considering three memos on updating preparations for a no-deal Brexit.
One is general preparations, one is about ports and airports and the third is about communicating with people who might be impacted.
However, Bloomberg has reported that the Government will accept in documents that checks will need to happen on or near the border, especially for livestock.
That has been strongly denied by Government sources, who have always said infrastructure near the border is not being considered.
It is expected the full documents will be published later today.