Piara Khabra, the Labour MP for Ealing Southall, has died at the age of 82, his parliamentary researcher Julian Bell said.
Mr Khabra, who was the oldest Member of the House, had been undergoing treatment for liver problems at Hammersmith Hospital, west London.
Originally from the Punjab in India, he came to Britain in the 1950s and in 1992 he became one of the first Asian MPs to be elected in the post-war period.
Before entering he was a teacher and was actively involved in community politics as a Labour councillor and through the Indian Workers Association in Southall.
He led the fight against the far right in Southall in the 1970s and early 1980s.
Mr Bell said: "Piara Khabra was a remarkable servant of the people, devoting his life to helping his constituents and providing service to the community.
"At an age when most people had long since retired he was still energetically tackling individual and constituency problems. His service and political wisdom will be sadly missed."
Labour Party chairman Hazel Blears paid tribute to Mr Khabra, saying: "Piara was a stalwart of the Labour movement and a strong representative for his constituency. He will be sorely missed in his community, in Parliament and in the Labour Party."
Mr Khabra's death will mean an early by-election test for Gordon Brown, who takes over next week as Labour leader and Prime Minister.
At the last General Election, Mr Khabra held Ealing Southall with a comfortable 11,440 majority over the Liberal Democrats, who were second.
