Ruairí O Bradaigh, whose life-long commitment to an interpretation of Irish republicanism was matched only by the fervour with which he opposed any compromising, as he saw it, of its principles, has died aged 80.

Des Dalton, his successor as president of Republican Sinn Féin, the party he founded in 1986, eulogised him last night as "a towering figure of Irish Republicanism in the latter half of the 20th century". "

He came to embody the very essence of the Republican tradition, setting the very highest standards of commitment, duty, honour and loyalty to the cause of Irish freedom,” said Mr Dalton.

Gerry Adams, the president of Sinn Féin who was loathed by O Bradaigh, spoke of his "sadness" at his death. "On behalf of Sinn Féin, I want to extend my sincere condolences to his family and friends," said Mr Adams, adding: "Whatever differences we may have shared on political matters Ruairí was a life-long activist who was committed to his principles."