The number of people in Britain applying for Irish passports exceeded the number of applications received from Northern Ireland last year.
Statistics show there were 81,287 applications from Britain and 80,964 from the North.
The figures cover the period from January to December 10th 2017.
Fianna Fáil spokesperson on foreign affairs, Darragh O'Brien obtained the figures through a parliamentary question he tabled to Foreign Affairs Minister Simon Coveney.
Commenting on the figures, Deputy O'Brien said the surge in applications for an Irish passport from both the North and Britain will place further demand on an already pressurised passport services.
"Holding an Irish passport has always given citizens unique status across the globe, and has become a well-respected symbol of free movement.
"For the first time ever the number of passport applications received from Britain has exceeded the number received from the North.
"Since 2012, the number of applications for a Republic of Ireland passport from Northern Ireland has more than doubled.
"Many are now applying for a passport out of fear as opposed to requirement or necessity.
"The total number of Irish passport applications received from Northern Ireland and Britain is just over 160,000 and this is likely to have increased by the end of 2017."
"Changes will need to be made"
The number of those applying for an Irish passport is being attributed to the UK's decision to leave the European Union.
Mr O'Brien added: "Our current passport office is coming under growing pressure and the latest surge exposes the need to examine the current capacity to process these applications.
"It is probable that changes will need to be made to procedures in order to cater for this increased level of demand and I intend to explore what additional resources will be available with the foreign affairs minister."
The Irish passport was recently ranked the fifth highest in the world, in terms of the number of countries their holders can travel to visa-free.