Richard Boyd Barrett has accused the European Commission President of 'betrayal' over border checks in the event of a no-deal Brexit.
The People Before Profit TD says weekend comments by Jean Claude Juncker that a no-deal would mean a hard border are the complete opposite of what he told the Dáil.
Mr Boyd Barrett says there is a 'blame game' going on and peace is hanging in the balance.
"I think it's really scandalous, Jean Claude Juncker said that Europe could be trusted on the issue of the border and now he's saying that if they can't come to an arrangement with Boris Johnson that the European Union will impose a border," said Mr Boyd Barrett.
"This would seriously endanger peace on this island.
That really is a betrayal of the comments he made to the Dáil.
"We all know Boris Johnson doesn't care about Ireland or the border but really it is deeply shocking that the European Union now seems to be willing to sacrifice peace and stability on this island in order to protect a market and impose a hard border which would be a disaster."
The prospect of a no-deal Brexit is also causing concern over the impact it could have on non-EU relatives of British people living in Ireland.
Many people have been receiving letters from authorities here about the prospect of losing some EU rights, once Britain leaves the EU.
Legal Executive, Siobhan Clabby's husband Matthew is from New Zealand says the prospect of a no-deal Brexit is creating a lot of uncertainty for British people and their spouses in Ireland.
"What does it mean going forward? Does it mean that we will have to move back to Sydney or New Zealand?
"He has residency in Sydney as well.
"After moving to Ireland and becoming so happy here, we're delighted to live here.
"The idea of having to go back to the other side of the world or the UK where I don't have any roots, they are not great solutions."