Long-serving Labour backbencher Sir Stuart Bell has died after a short battle with pancreatic cancer, his family has said.
The 74-year-old had been MP for Middlesbrough for nearly three decades and served in key positions in Parliament.
He passed away at his home with his family around him.
Sir Stuart was the son of a Durham miner and, after a grammar school education, worked briefly as a colliery clerk and newspaper reporter before becoming a barrister.
Having lived and worked in Paris, he returned in 1977 to pursue a career in politics.
He unsuccessfully contested Hexham in 1979 and was a member of Newcastle City Council until he won Middlesbrough in 1983. He went on to hold the seat through seven general elections.
While never serving as a minister, Sir Stuart was the party's Northern Ireland spokesman during the 1980s.
Later in his career he was handed a powerful role on the Commons Commission - the body responsible for running the House.
Sir Stuart was criticised last year after his local newspaper tried to call him more than 100 times and said the phone was never picked up. He was forced to defend his actions, which he called a "misinterpretation", to Labour leader Ed Miliband.
David Cameron paid tribute to Sir Stuart's "three decades" in Parliament: "Sir Stuart was one of Parliament's great characters. Throughout his three decades in the House of Commons, he always stood up for those issues he cared most deeply about.
"A firm advocate of church matters as Second Church Estates Commissioner for thirteen years, and a member of the House of Commons Commission over a very challenging decade, he will be remembered for his kindness and his courtesy towards Parliamentary colleagues.
"My thoughts go out to Stuart's wife, Margaret, and his family at this very sad time."
Sir Stuart, who was married with one son, was knighted in 2004 for "services to Parliament" and was also awarded the Legion d'Honneur in 2006 for his contributions to Anglo-French relations.
Among his political missions was to secure voting reform, leading Labour campaigns for a switch to AV - but he was an active opponent of the party's proposals to replace the House of Lords with a senate.
Labour former Europe minister Chris Bryant paid tribute to the "ardent and intelligent pro-European Labour MP" as parliamentary colleagues began to register their sorrow at his death via Twitter.
Ian Swales, the Liberal Democrat MP for neighbouring Redcar, wrote: "Very sad to hear of the death of Stuart Bell MP. Always a total gentleman to me."