The death has taken place of the former Cabinet minister and journalist Conor Cruise O'Brien.
Mr Cruise O'Brien, who was 91, served as Minister for Posts and Telegraph during the Fine Gael/Labour coalition in the 1970s.
His cabinet job covered broadcasting and as violence intensified in Northern Ireland he became embroiled in the controversy about a ban on members of Sinn Féin and the IRA having access to the airwaves.
Mr Cruise O'Brien strongly supported the ban, introduced uncer S 31 of the Broadcasting Acts, and current Labour leader Eamon Gilmore praised his 'immense political courage'.
'Although threatened on many occasions...he never shirked from challenging and taking on the nationalist paramilitaries," Mr Gilmore said.
Dr Cruise O'Brien was also a civil servant, a UN official, a writer, an academic and a newspaper editor.
He studied History and Literature in Trinity College and was the author of several books, including States of Ireland, which examined the relationship between Catholics and Protestants in Northern Ireland.
His plays include Murderous Angels and King Herald Explains.
He joined the civil service at 25, before later going to external affairs and then becoming a delegate to the UN Assembly.
In 1969, he was elected to the Dáil as a member of the Labour Party and he became the party's spokesman on Northern Ireland.
He became Minister for Posts and Telegraphs in 1973 but lost his seat in 1977.
Taoiseach Brian Cowen has expressed his condolences to the family of Mr O'Brien, who he said was a leading figure in Irish life in many spheres since the 1960s.
'(He) was blessed with a strong intellect and he was a man of strong convictions. I never doubted his sincerity or his commitment to a better and more peaceful Ireland,' Mr Cowen added.
Minister for Foreign Affairs Micheál Martin said: 'Conor Cruise O'Brien made a remarkable contribution to Irish life over many decades.
'He was a scholar and writer of international distinction, an outstanding diplomat in the service both of Ireland and of the United Nations, and a robust and highly influential participant in the politics of our island.
'He was a man of undoubted courage and brilliance.'