Tony Benn was a great speaker , made the hairs on the back of my neck stand up several times , listening to him at the Tolpuddle Martyrs. RIP Tony Benn...
His death comes just days after the loss of a left-wing hero of a later generation, RMT union boss Bob Crow.
Labour MP Dennis Skinner, who had known and worked with Been since 1970 and campaigned alongside him during the miner's strike of 1984/85, said: "He was one of the greatest assets the Labour Party has ever had.
"He was a campaigner and a teacher. His whole idea was about trying to influence people, not just in Parliament but outside too."
The chair of the Socialist Campaign Group of MPs, John McDonnell, said: "Tony Benn was the articulate advocate of socialism who inspired my generation and gave us all hope of a fair and equal society.
"He will be remembered for his principled commitment to his socialist beliefs and his principled stand on so many issues. His passing adds to a terribly sad week for the Left, coming so soon after the loss of Bob Crow."
Former foreign secretary Dame Margaret Beckett described him as "delightful, friendly, very open-minded and interested always in new ideas".
She told BBC Radio 4's Today programme: " He had such clarity of expression, he opened people's eyes and he made them think.
"He made enemies and kept enemies but on the whole I think most people regarded him with a good degree of affection, long before he got sufficiently old - as he said himself - that he can't do any more harm."
Former Cabinet minister Peter Hain said: "Tony Benn was a giant of socialism who encouraged me to join Labour in 1977, a wonderful inspirational speaker and person who will be deeply missed."
Labour's former spin doctor Alastair Campbell tweeted: "RIP Tony Benn. A fighter all his life, fought death with the same courage he lived life. A large and loving family there with him to the end."