The former president of the Workers' Party Seán Garland has died at the age of 84.
Mr Garland died at his home in Navan, Co Meath after a long illness.
He is survived by his wife Mary, daughter Caoimhe, and two grandchildren.
Mr Garland was a member of the IRA during the 1950s, '60s and '70s, and was a key figure in the Official IRA ceasefire in 1972.
He was arrested in 2005 in Northern Ireland on foot of a US extradition warrant, and was arrested again in 2009 after he fled to Dublin.
In January 2012, the High Court found that the US had no jurisdiction to extradite him.
The Workers Party paid tribute to Mr Garland, describing him as "a life-long comrade, a member of the Party’s Central Executive Committee and one of the people who most influenced and shaped the Workers Party over many decades".
Party president Michael Donnelly said that he was “a unique and charismatic individual whose contribution to Irish political life cannot be overestimated”.
“Sean never took the easy option or the path of least resistance. He always based his decisions, and his actions, on what he adjudged to be in the best interests of working class people and the revolutionary socialist project.
"Comrade Sean Garland devoted his life to the struggle to build a socialist future.
"We extend our deepest sympathy to his family at this time. We have all lost a fearless revolutionary standard bearer, a colossus of socialist politics, a comrade and friend," Mr Donnelly said.