The European Commissioner for Agriculture, Phil Hogan, has said the EU will "not buckle" in the face of a no-deal Brexit.
He said nothing had changed on the EU side and "detailed contingency plans for every outcome" had been made and the EU "would not be found wanting".
Speaking at the Thomas D'Arcy McGee Summer School in Carlingford, Mr Hogan said that contrary to British Prime Minister Boris Johnson's view, the backstop was not "anti-democratic" and the British government needed to "get real" about the importance of the backstop and what it represents.
The former Fine Gael TD added that if the UK opts for a hard Brexit, it will be harming itself.
He said while it will mean "pain" for everyone, the worst pain will be felt by the people of the UK.
Mr Hogan said gambling with peace and the Good Friday Agreement was "not good politics".
He accused Mr Johnson, like both his predecessors, of putting the best interests of the Tory party ahead of the best interests of the UK.
Referring to the letter written by Mr Johnson to Donald Tusk this week, in which he said the backstop was anti- democratic, Mr Hogan said this was strange coming from "an un-elected prime minister" who had previously voted to support the backstop.
He also said the UK should be under no illusion [if it fails to prevent a crash-out of the EU] about "the foul atmosphere" it will create with its EU partners and the "serious consequences" this will have for negotiating any future trade deal.
In his closing remarks, Mr Hogan referenced Mr Johnson's desire to be seen as a modern day Winston Churchill.
He said the British government's only Churchillian legacy in the event of a no-deal Brexit will be "never have so few done so much damage to so many".