Tanaiste Simon Coveney has contradicted Taoiseach Leo Varadkar's assertion that checks may have to be set up near the border in the event of a no-deal Brexit.
Mr Coveney said he does not expect they will be near the border, though they will have to take place "somewhere".
Irish officials are back in talks with the EU Commission this week on what will happen and how the EU single market can be protected if the UK crashes out on October 31.
However, the Tanaiste can still not say when businesses will be told of the plan.
"First of all, we won't sign up to any agreement that requires checks with the UK in terms of a permanent trading relationship linked to Brexit, " he said.
Mr Coveney said any checks would be a "temporary, emergency measure" to protect Ireland's place in the single market.
He said he would have clarity on the location of the checks before the UK leaves the EU on October 31.
"The response to a no-deal Brexit will be checks somewhere. I don't think they will be near the border," he said.
Earlier this month, Mr Varadkar told a British-Irish Chamber event that checks near the border were "a possibility we may have to live with for a period".
Ministers had yet another lengthy session on Brexit at yesterday's cabinet meeting, including a discussion on how the country will react on Nov- ember 1.
Mr Coveney said that for now the priority must be trying to secure a deal, though planning for a no-deal continues.
He confirmed that while the British government has yet to put forward written proposals on the backstop, there have been discussions on possible ways forward.
It is understood these talks have included the idea that the backstop could apply to Northern Ireland only rather than the whole of the UK.
"We in the EU are open to a deal, but it must achieve the aims of the backstop through a legally operable solution," Mr Coveney said.
"We await written proposals from the UK side. We simply haven't seen any written proposals to date.
"Just because prime minister Boris Johnson says the backstop needs to go, it doesn't mean everyone else will respond positively to that.
"That's because we know the consequences of a no-deal Brexit are significant and pose huge challenges for Ireland, north and south."