Democratic Unionist MP Ian Paisley Junior advised people in Northern Ireland to get Irish passports following the Brexit vote result.
His advice came as a big increase in applications for Irish passports for residents in the North and in Britain is expected.
Mr Paisley, who campaigned with the DUP for a Leave result, said on Twitter: "My advice is if you are entitled to a second passport then take one.
"I sign off lots of applications for constituents.
"My advice is to take as many as you can, especially if you travel to different world trouble zones."
Belfast's Central Post Office ran out of application forms for Irish passports on Saturday because of heavy demand.
A Department of Foreign Affairs spokeswoman told the Irish Independent that entitlements to Irish citizenship and passports for those born on the island of Ireland, and those claiming citizenship through parents or grandparents born in Ireland, are "unchanged" after the referendum result on Friday.
She said: "There has been an increase in queries in respect of entitlements to Irish passports."
In the past decade, more than 90,000 people born in Britain have received Irish passports.
And more than 150,000 people born in Northern Ireland received Irish passports in the same period.
Calls for Ireland to try to sweep up high value banking jobs from Britain in the wake of the Brexit referendum are well meaning, but are getting ahead of the priority, which is to contain this major new economic threat.
The week's political and economic pivot will be the European Council meeting in Brussels tomorrow and Wednesday, when outgoing British Prime Minister David Cameron will face fellow EU heads of government for the first time since his country voted last Thursday to leave the European Union.