Former EU commissioner Mr Peter Sutherland says he will not be using the title of "Sir" following his receipt this week of a British honorary knighthood.
Asked by The Irish Times whether he would be adopting the title, Mr Sutherland replied: "Of course not."
He said: "As an Irish citizen who has taken an honorary knighthood, as opposed to a knighthood, I neither will, nor could, use a title."
Irish citizens can adopt a title if they also hold British citizenship, which is available to people born in the Republic prior to January 1st, 1949.
But Mr Sutherland, who was born in Dublin in 1946, has chosen not to avail of dual citizenship. This contrasts with Sir Anthony O'Reilly who was awarded a knighthood in the British new year's honours list of 2001.
Sir Anthony claims to have held dual Irish and British citizenship since his birth. Before accepting his knighthood, the businessman and newspaper magnate obtained the permission of the Government in accordance with Article 40.2.2 of the Constitution.
The Article states that "no title of nobility or honour may be accepted by any citizen except with the prior approval of the Government". The requirement only applies to full honours, to which titles are attached, and does not apply to honorary awards like that bestowed on Mr Sutherland.
The rock star and campaigner Bob Geldof and singer Daniel O'Donnell are among a range of Irish citizens to have previously received honorary awards, for which the recipient is not required to kneel before Queen Elizabeth.
Mr Sutherland received the award from Prince Charles on Wednesday at a ceremony at Clarence House, the prince's official residence in London. In a statement from the European oil giant BP, of which Mr Sutherland is chairman, his knighthood was placed in the context of a "select group of non-British citizens", including former South African president Mr Nelson Mandela and the ex-mayor of New York Mr Rudy Giuliani, who previously received honorary awards from the queen.
Mr Sutherland is the first former member of an Irish government to receive an honorary knighthood since the foundation of the State. A former barrister who served as attorney general for two terms under Mr Garret FitzGerald, Mr Sutherland became a European commissioner and subsequently the director-general of the World Trade Organisation in 1994.