Albert Reynolds told John Major that Ireland is “not ruled by Rome”, during a meeting in which the Irish side expressed frustration at the attitude of unionists to talks on Northern Ireland.
According to a confidential document, the comments were made at a meeting between Mr Reynolds and the British PM in Downing Street on 16 June 1993.
After that meeting, both called for talks between Northern Ireland political parties to resume.
Behind closed doors, Mr Reynolds vented his frustrations with Ulster Unionist Party leader Jim Molyneaux.
He said: “I have always had reservations about Jim Molyneaux. Looking at the situation from his perspective, what is in it for him?
“However, he has some very good people behind him. How can we harness them to support resumption of talks?”
In a later exchange, Tanaiste Dick Spring admits he is worried up the upcoming European elections, warning: “[Ian] Paisley will start campaigning but there is no real benefit in this for the people in Northern Ireland.”
Mr Reynolds picks up the conversation: “The Unionists feel they are under siege. Also, there is fear of demographic changes. Genuine people want to talk but fears are there.”
According to the memo, Mr Major tells the Irish delegation: “A large part of the Catholic population would not vote for a united Ireland – that is what is said.
“The question is how do we carry the Unionists? We can take them warmly by – or try to persuade them to talk. We could see say to them we will see you alright (from a Parliamentary perspective) but we have not. What can we do?”
Mr Major suggests that the Taoiseach or the Tanaiste should make another speech to address the worries of unionists, referring positively to a recent speech given by Mr Spring.
The Secretary of State for Northern Ireland Patrick Mayhew urges Mr Reynolds to do the same, pointing to unionist concerns regarding articles two and three of the Irish Constitution and the recent judgment of the Irish Supreme Court in the “McGimpsey case”, which saw a challenge to the legality of the Anglo-Irish Agreement.