Former Taoiseach Bertie Ahern has dismissed the idea that border checks could be beefed up in the Republic to control immigration into Britain.
Mr Ahern said that it was illogical to think that Irish ports and airports would become proxy points of entry into the UK to avoid a hard border on the island of Ireland.
The suggestion was mooted in recent weeks, with the Northern Ireland Secretary James Brokenshire adding that governments in London and Dublin would work to strengthen the Republic's external borders once the UK withdraws from the EU, on a date yet to be decided.
However, Mr Ahern said the Irish Government should not support such a move. "I can't imagine it happening," the former Taoiseach said.
Mr Ahern added that the Republic should not have any right to interrogate a plane load of passengers coming into Dublin from another European Union country.
"Imagine if the same was to happen to Irish people going to EU countries," he told Newstalk radio.
"Say if you and I today were going over to a conference or a football game or rugby match or whatever and we were to get that interrogation with our EU passport.
"We don't mind being checked. We don't mind producing it. But to start being questioned is not logical."