BARONESS Castle, one-time MP for Blackburn, has died aged 91 her family have announced.

Elected MP for the town in 1945, she held the seat for more than 30 years.

Her family said in a statement: "Baroness Castle of Blackburn died peacefully in her sleep at her home in Buckinghamshire earlier this afternoon with her family at her bedside."

Tony Blair led the flood of tributes to Baroness Castle, describing her as "a great heroine".

He said she 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 - courageous, determined, tireless and principled, she was never afraid to speak her mind or stand up for her beliefs."

"Britain has lost one of its great political figures and the Labour movement a great heroine."

Baroness Boothroyd, the former Commons Speaker, who was once Barbara Castle's secretary, said: "Barbara never retired from active politics. Her death creates a vacuum on the political scene.

"She was an indomitable fighter for women's rights. In recent years she championed the cause of pensioners. Barbara could always be found campaigning for her deeply held socialist beliefs."

Lady Boothroyd continued: "Importantly, to me, Barbara was a true friend and mentor."

Next month, Lady Boothroyd, Chancellor of the Open University, was to have presented Lady Castle with an honorary doctorate of the University.

"I am deeply saddened that she did not live long enough to receive it from my hands."