Taoiseach Enda Kenny has described the prospect of a British exit from the European Union as "a major strategic risk for Ireland", adding that this State's commitment to the EU is "clear and unqualified".
Addressing the annual conference of the Confederation of British Industry (CBI) in London, Mr Kenny said he believed it was in Britain's interest to remain in the EU, but stressed that the decision was a matter for Britain's people.
“But I think it is right - as your friend, closest neighbour and the only EU partner with whom Britain shares a land border - to share our perspective with you. The Irish Government’s strong view, backed up by independent economic research published last week, is that a Brexit is not in Ireland’s economic interest,” the Taoiseach said.
"The research showed adverse impacts across a range of headings including trade, energy and the labour market. It also debunked the myth that there would be some FDI bonanza for Ireland if Britain left the union."
He said the EU had been an important, perhaps underestimated, enabler of peace in Northern Ireland, instrumental in facilitating constructive contact and building trust between our governments to find a political settlement. All-island economic cooperation could be more difficult between two states that were not part of the EU.
He said: “The EU provided almost €2.4 billion in funding over the period 2007 to 2013 to help Northern Ireland overcome the challenges of a peripheral region that has emerged from conflict.
“Common membership of the EU project is part of the glue holding that transition process together... So I have no doubt that continued British membership of the European Union is good for Ireland and for relationships on these islands.”
Mr Kenny said that although the EU had contributed hugely to healing "a broken and divided continent" after the second World War, he agreed with British prime minister David Cameron that it could do better and that it had been subjected to unprecedented challenges in recent years.
“I share the view that we need to look critically at what we do at EU level and how we do it, to ensure the best deal for all our citizens. It is in all of our interests to make the union function more effectively,” he said.
Mr Cameron is due to outline his demands for a reformed relationship with the EU in a letter to European Council president Donald Tusk on Monday.
The Taoiseach said Ireland shared the prime minister’s priorities in economic policy, where Britain is seeking further market liberalisation within the EU and more trade agreements with the world outside it.
“Looking at these three areas of policy - single market, digital single market and trade agreements - it is clear that ongoing cooperation between the UK and Ireland will be important. We, and indeed other partners, want to continue working with the UK - a UK which is committed to staying and fighting its corner,” he said.
Mr Kenny was more cautious about Britain's other demands, which are expected to focus on the relationship between the euro zone and EU countries that do not use the euro; curbs on welfare payments to migrants from within the EU; and an end to the universal obligation on EU member-states to pursue "ever closer union" within Europe.
“I have always been clear that Ireland will be open and pragmatic when it comes to sensible proposals to improve the EU. In general, where the UK seeks reasonable and achievable adjustments, we will be sympathetic and supportive,” the Taoiseach said.
“In advance of detailed proposals it is difficult to be definitive on the other questions which have been raised. However, I believe that it should be possible, although sometimes not easy, to reach agreed and reasonable outcomes across the board.”
Addressing the conference immediately ahead of the Taoiseach, Mr Cameron said if Britain’s EU partners agreed to his reform agenda, he would campaign vigorously to remain in the EU.
He said that although Britain could survive outside the EU, the question the referendum on its membership should address is how Britain can be stronger and more prosperous. He said his essential demand was for greater flexibility, so the euro zone could integrate more if it chose to but that Britain should not have to follow suit.
“What I want is a live-and-let-live Europe, a flexible Europe,” he said.