A British exit from the EU would lead to job losses and trade decline in Ireland, Fine Gael MEP Sean Kelly has said.
Mr Kelly was speaking in the European Parliament this week, after British Prime Minister David Cameron outlined the reforms he wants the EU to introduce in order to entice the British people to stay within the Union.
Mr Kelly said he thought it was possible for the EU to introduce those changes.
"It would be a disaster for Ireland if the United Kingdom left, because it would mean that our trade would actually drop about 20%, which would mean a lot of job losses etc," he said.
"We are entitled to get our opinion across, but obviously don’t want to interfere directly with the referendum."
Meanwhile, Downing Street has denied that David Cameron is planning to drop his demand for a ban on in-work benefits for new EU migrants in the face of opposition from European capitals.
The Times quoted an unnamed European diplomat as saying that the proposal for workers from the 27 other EU states to be denied benefits until they have been in the UK for four years “does not fly”.
The diplomat said EU institutions were expecting Mr Cameron to come forward with new proposals at December’s summit of the European Council, when he is hoping to get agreement from fellow national leaders on a package of reforms to the UK’s membership.
But a Number 10 spokesman insisted there was no change to the proposals set out by David Cameron in a letter to European Council president Donald Tusk earlier this month.
“The position has not changed from the letter the Prime Minister sent to the Council president,” the spokesman told a Westminster media briefing.
Mr Cameron fuelled speculation that he may be willing to make concessions on the benefit proposals when he said he was “open to different ways of dealing with this issue”.
In a speech as he published the letter on November 10, the PM said: “We have proposed that people coming to Britain from the EU must live here and contribute for four years before they qualify for in-work benefits or social housing, and that we should end the practice of sending child benefit overseas.
“Now, I understand how difficult some of these welfare issues are for other member states, and I am open to different ways of dealing with this issue.”
Mr Cameron is expected to speak with Mr Tusk and European Commission president Jean-Claude Juncker ahead of the December 17 summit in Brussels to assess the chances of securing agreement, which would allow him to proceed with the promised in/out referendum in early 2016.