FIANNA Fáil leader Micheál Martin says former foreign secretary Boris Johnson was not dealing in reality when it came to Brexit.
Mr Johnson resigned on Monday night after claiming Prime Minister Theresa May was leading the UK to a semi-Brexit from the EU, a move that the Fianna Fáil leader said was revealing in itself.
He added: "The stance of hard-line Brexiteers is revealing, Boris Johnson's resignation letter to Theresa May in itself reveals actually the degree the type of Brexit he wanted was never going to happen, and he was never really dealing with reality.
"He said it here in Dublin last year, that he didn't want a Norway type agreement because he felt that Britain would be rule takers - and that's the fundamental difficulty, Brexiteers are failing to grasp that when you enter an agreement with 27 other countries you agree to share a sovereignty.
"I wouldn't personalise it, but what struck me when I met him he kept telling us it'll be alright, when I referenced the revenue report and how catastrophic a hard Brexit would be, he simply said that we must make sure that never happens, but gave no details.
"He was not across the full detail of Brexit, he had a wildly optimistic view that was never grounded in reality.
"When he says the Brexit dream is dying, he's really talking about the perspective he had on Brexit, but in my view that was never a live possibility in any instance."
Mr Martin added he had confidence that Theresa May had cleared a path for coherent negotiations between the UK and EU and in light of the recent developments was optimistic the border issue could be resolved.
"From an Irish perspective, negotiations are key to Ireland's future in terms of the final impact a deal would have on our trade and growth as a country.
"The relationship that emerges between EU and UK could resolved border issue, there is a huge determination to solve the border issue on all sides and it is do-able.
"It's regrettable it hasn't been resolved yet, I think there should be less hype and over spinning and let's focus on detailed negotiations.
"I think there will be more give and take but I'm not underestimating the challenges.
"I don't believe it's beyond the capacity of EU and UK to work out what will be very difficult issues," he said.
