The only certainty about Brexit is that it will be a "negative-sum game for all concerned," the former Fine Gael leader Alan Dukes told the MacGill Summer School in Glenties, Co Donegal on Monday.
Mr Dukes said that the process of the United Kingdom quitting the European union would be "complex and fraught with political, technical and legal difficulties" and that Ireland had "more to lose" than any other of the 26 countries of the EU, excluding the UK.
He also said that the UK had more to lose from Brexit than any of the other 27 EU countries.
The theme of the summer school is global turbulence: Ireland and Europe must prepare for a new era and on Monday a full house in the Highlands Hotel in Glenties heard speakers address the certainties, the uncertainties and the unknowns of Brexit.
Mr Dukes, a former minister for finance, said there were a number of possible outcomes to the Brexit negotiations, one of which was that the UK “falls off a cliff” and becomes a “third country” as far as the EU27 was concerned.
Other possibilities included the UK and the EU agreeing some special arrangements similar to Norway where Britain would continue to have special trading status with Europe.
Another possibility was that if no agreement was struck between the EU and the UK by the March 2019 deadline that the both sides would “prolong the agony” by extending the negotiating period.
“The militant pro-Brexit tendency in the UK would be likely to regard this scenario with great suspicion as foot-dragging,” said Mr Dukes in a speech and in a paper he presented to the summer school on Monday.
Doublespeak
He added however that the real difficulty was that the British government had “put no flesh on the bones of the kind of arrangement it hopes to secure with the EU27”.
He was suspicious of a "doublespeak" emanating from the British government. Mr Dukes also was dismissive of a recent suggestion by former Irish diplomat Ray Bassett that Ireland should seriously consider leaving the EU, although he did not mention Mr Bassett by name.
“I agree that we should consider this possibility and its consequences – just as I believe that it is useful to consider the consequences before jumping out of an aeroplane without a parachute,” he said.
Dr Brendan Halligan said that among a number of certainties about Brexit was that it was "clear the United Kingdom is looking for the impossible".
He said the EU bill for the UK to quit Europe was a gross €100 billion which was being contested.
Dr Halligan said however that the EU had sequenced the negotiations so that the bill must be addressed in the early stages of discussions.
Dr Halligan, who is president of the Institute of International and European Affairs, told the audience that the British government’s opposition to the European Court of Justice was “visceral and irrational”.
He believed ultimately what was a certainty was that the UK would leave the customs union and the single market and that there would be an inevitable hard border.
Dr Halligan feared too that as a consequence Ireland and the European Union were facing into an "asymmetric economic shock".
MEP Marian Harkin said there was a real concern that "Brexit could spiral out of control".
There was a potential "uncertain and destabilising period" ahead for the UK. She said it was vital that the Belfast Agreement be protected in whatever agreement flows from the Brexit negotiations.
Many regions of the EU had forms of special status and "we need to start crafting" a system that would protect both the 1998 agreement and Northern Ireland, she added.
Pat Cox, the former president of the European Parliament, said that people should not be looking to the British Labour Party to "rescue" Ireland and the EU by agitating for a soft Brexit.
He said that on the big issues that would determine whether Brexit would be soft or hard, staying in or leaving the single market and the customs union, that it was “silent”.
