The possible implications of the UK leaving the EU, or Brexit, are unknown, according to Kenneth Clarke, the former UK Chancellor.

Speaking at an AIB debate on the possibility of the UK leaving the EU, or Brexit, Clarke said the honest truth is no one has a clue what the outcome will be.

“The economic and other issues have not been explored in debates in the UK, it’s all about personalities in the conservative party.”

However, he is staunchly in favour of the UK remaining within the EU, but not at any cost. He said it would be “extremely unwise” for the EU to be too generous in its arrangements with the UK and may encourage other countries to seek similar arrangements.

“It makes us a more powerful country being part of the EU. Those who dominated the world previously, the British, French and German have seen their powers decline as the US and China have grown in power.

“Collectively we still have great clout. I think in 50 years’ time America, China, India and the EU will be the four great powers.”

He said exiting the EU has uncertain economic consequences. “The economic consequences are very uncertain…I have never known a time when the outlook for the global economy was more uncertain. I am in the pessimist camp when I look at the future of the global economy….Brexit is the latest shock the British have introduced to the state of affairs.”

He also warned that major investment plans in both the UK and internationally have been put on hold to await the outcome of the UK’s referendum.

“Britain would look extremely unattractive to foreign investment (if it leaves the EU).”

Richard Pym, the Chairman of AIB, the main fear for Ireland if the UK leaves the EU is the knock of effects on the Irish economy.

“We may be sharing a land border but heading in completely different directions. If the EU punishes the UK for border controls, will it mean border and emigration controls along the Ireland and Northern Border?”

However, Dr Gerard Lyons, Boris Johnson’s Chief Economic Advisor, said Johnson’s decision to back a move by the UK to exit the EU was not politically driven.

He said the EU does not embrace reform and the eurozone is a failed project.

“It does not embrace its problems such as youth unemployment, immigration in Greece. These have not been adequately addressed.

“But the real economic problem is the eurozone – it’s like the eurozone tail wags the dogs. It’s a crazy economic project.”

“The EU is like the Titanic, the day it left Southampton people wished they were on that ship. Many people in Brussels are like those who sank in first class, oblivious to what is going on down below.”

He also said that the EU with the eurozone in place is likely to be the slow growth economy of the world and the UK should not want to be part of that.

Being one of 28 countries, he said, does not help the UK as its agenda is never centre stage and it would be better in a global market on its own.

“In this world. economies that can adapt and control their own destiny are those who will do well.

“The UK needs to be thinking globally and needs to adapt and be able to do so quickly. Europe is a slow growth region and we need to ensure that we are not held back by the EU.”

Simon McKeever, CEO Irish Exporters Association, told the forum that Ireland could not have a separate bilateral trade agreemtn with the UK. “If the EU takes a very hard line with the UK if it goes we may suffer most with tarrifs etc.”