Baroness Barbara Castle, a prominent cabinet minister in Labour Party governments in the 1960s and 1970s and a figurehead for both the left and women, died Friday aged 91, her family said.
"She died peacefully in her sleep with her family at her bedside," Ms Castle's family said in a statement.
British Prime Minister Mr Tony Blair hailed Ms Castle as a "great heroine" and a "pioneer" in women's rights.
"Barbara Castle was one of the dominating figures of the Labour movement of the last 50 years, a radical independent spirit and an extraordinary pioneer for women in politics," Mr Blair said in a tribute.
Respected for her sharp intellect and fierce tongue, Ms Castle was frequently compared to another pioneer in British politics, Lady Margaret Thatcher.
Born on October 6, 1910 into a strongly left-wing family in the northern English county of Yorkshire, Ms Castle first became active in the Labour Party in the 1920's, and served briefly as a journalist, for the pro-Labour Daily Mirror, in the last year of World War II.
Between 1958 and 1959 she was chairwoman of the Labour Party, a largely administrative post which is below that of party leader.
She rose to national prominence under when Mr Harold Wilson ended 13 continuous years of rule by the Conservative Party by winning an election in 1964.
Barbara Castle received a life peerage in 1990, becoming Baroness Castle of Blackburn.
Her memoirs were published in 1993, entitled Fighting All the Way, and, as the title suggests, there were no holds barred.
AFP