The number of British passport holders applying for the Irish counterpart has soared by 69 per cent in the first quarter of 2017.
There have so far been 51,079 applications from Brits this year and a total of 250,000 Irish passports were issued in that timeframe.
The number of issued passports is predicted to reach one million by the end of 2017.
Last year, 733,060 passports were issued, up nine per cent on 2015. About 65,000 of those were for Great Britain and Northern Ireland citizens.
The three months following the Brexit referendum saw the biggest surge for UK applications, with 83 per cent more than the year before.
Foreign minister Charlie Flanagan believes people are trying to hold onto their citizenship in the EU.
He told the Guardian: “It’s reasonable to suggest that Brexit is a factor in what are record numbers of applications.
“I think it’s also reasonable to assume that there are large numbers of people of Irish descent who now feel that they would like to remain as EU citizens in what is a changing time in relations between Ireland and the UK.”
The sharp increase has led to extra staff being hired by the department and the introduction of an online passport renewal service.
Ireland’s population stood at almost five million during the 2016 census.
Residents of Northern Ireland are entitled to both Irish and EU citizenship under the Good Friday agreement of 1998.
Flanagan said the immediate surge in applications post-Brexit vote in June was due to a “sense of concern” about the future.
