IMF warns the consequences of the UK quitting the EU range from "pretty bad to very, very bad"
The Taoiseach has called on the UK to stay in the EU - saying Ireland would be 'severely impacted' if they left.
Enda Kenny said that a number of studies have shown that we will be hit economically if there is a Brexit.
He added that development in Northern Ireland is dependent on the UK staying in the European Union.
Enda Kenny called for Irish people in the UK to vote to stay.
He said that while "nobody likes to be lectured by anybody else", Ireland has had a "unique arrangement with Britain since the 20s".
The Taoiseach's comments came as the IMF warned the consequences of the UK quitting the EU range from "pretty bad to very, very bad".
Christine Largarde, managing director of the global finance body, said a sharp rise in interest rates were among the negative impacts that could result from the UK leaving the 28-member bloc in the referendum on 23 June.
She also said Brexit carried a "significant downside risk" and that the prospect was causing "anxiety around the world".
Ms Lagarde was speaking as the IMF published a report which said a departure from the EU would lead to a "protracted period of heightened uncertainty" for the UK with a hit to output and "sizeable" long-term losses in income.
The reaction of world markets was also likely to be "negative and could be severe", the report said.