A UK withdrawal from Europe would be a major setback for Irish economic recovery, according to a new report.
Ibec, which represents Irish business, has warned that a Brexit could have far-reaching consequences for the UK's nearest neighbour.
Pat Ivory, Ibec director of EU and international affairs said: "A UK departure would be a blow to the Irish recovery and result in a protracted period of uncertainty for business."
Launching its report which which focuses on five major impacts, Ibec said it was important that Irish concerns were heard and understood in the debate.
Topping the list of concerns is the potential undermining of the all-island economy.
The report states: "A UK departure from the EU would remove a shared economic, political and legal backdrop and could set back positive political and economic developments of recent years."
There are also warnings that trade flows between Ireland and the UK could fall by up to 20% with the food sector exports likely to be hit hardest and that weakened exchange rates could hamper competition.
The new report also highlights fears about the "damaging economic effect" of investment uncertainty and the potential impact on energy supplies.
Mr Ivory added: "It would undermine Europe's ability to act collectively and decisively in the world and could push the EU back into a dangerous period of crisis management. The UK and Ireland have been close allies in Europe across a wide range of areas.
"An EU without the UK would be a lesser union."
Meanwhile, Ibec has also stressed the growing need for a stable domestic political backdrop and has called for a "speedy, comprehensive agreement to be reached between the main political parties".
"A vote to leave would demand an immediate, considered and sophisticated response to minimise instability and ensure Irish interests are safeguarded in any subsequent negotiation and settlement," an Ibec statement said.
