The possibility of a Brexit will top the agenda in talks between the acting Foreign Affairs Minister and his UK counterpart today.
Charlie Flanagan is in London for a series of engagements, including a meeting with Britain's Foreign Secretary Philip Hammond.
The two foreign secretaries will speak about several pressing issues facing Ireland, the UK and Europe - including the refugee crisis, terrorism and the UK's referendum on membership of the EU in June.
Minister Flanagan will also meet figures in Irish community groups in the UK, as well as members of the UK Labour Party and British-Irish business networks, in a bid to consolidate support among Irish people in Britain.
Irish citizens resident in the UK are eligible to vote in the upcoming referendum.
Irish trade with the UK is worth €62bn a year, and there are strong fears that Britain outside the EU would negatively impact that trade - as well as political relations vis-á-vis Northern Ireland.
Speaking ahead of his meeting with Mr Hammond, Minister Flanagan said “I fully respect that the question of the UK’s membership is for its electorate to decide.
"In my series of meetings in London, I will offer Ireland’s unique perspective as a neighbour, as a fellow EU member state, as a €62 billion-a-year trading partner, as a partner in transforming British Irish relations and as a facilitator of successive agreements aimed at securing peace and prosperity in Northern Ireland," he added.
Today's meeting comes as David Cameron claims leaving the EU would be an "act of economic and political self-harm."
Writing in this morning's Telegraph, the British Prime Minister says exiting the single market would be "needless and reckless" and would not help the UK steel industry.