Labour MP Jack Dromey died suddenly in his flat in Birmingham on Friday morning, the shadow minister’s family said.
Dromey, 73, married to fellow Labour MP Harriet Harman, was understood to have died from natural causes.
The politician had represented Birmingham Erdington since 2010 and contributed to a parliament debate as recently as Thursday.
Dromey and Harman’s son, Joe, tweeted: “Our dad – Jack – died suddenly today. We loved him so, so much. Rest in peace big man x.”
A statement issued on behalf of the family of the Birmingham Erdington MP said: “Jack Dromey MP died suddenly this morning aged 73 in his flat in Erdington.
“He had been a dedicated Member of Parliament for Birmingham Erdington since 2010.
“He was a much loved husband, father and grandfather, and he will be greatly missed.”
Labour leader Keir Starmer paid tribute to Dromey as an MP who “lived his commitment to social justice every day”.
Starmer said: “The proud son of Irish parents, Jack Dromey dedicated his life to standing up for working people through the Labour movement, becoming deputy general secretary of the UK’s largest trade union and then a Labour MP.
“From supporting the strike at the Grunwick film processing laboratory, when he met Harriet, through to being elected to represent Birmingham Erdington in 2010, Jack lived his commitment to social justice every day.
“Jack was recognised for his determination to stand up for his constituents and he was highly respected and warmly regarded across parliament.
“My thoughts and those of the whole Labour movement are with Harriet, their children and all those who knew and loved Jack.”
Commons Speaker Lindsay Hoyle said MPs are in “disbelief that the life-force that was Jack Dromey has died”.
In a statement, Hoyle said: “We are all in disbelief that the life-force that was Jack Dromey has died, this is another sad day for the House and a bad start to the year.
“I have known Jack since the mid-1980s when we fought to save the Royal Ordnance Factory in Chorley, he was national officer for the Transport and General Workers’ Union, and I was chair of economic development at Chorley Council.
“He was a great guy, down to earth, always positive and always looking to support and save jobs.
“At his heart he was a devoted husband, father and grandfather, so all our thoughts go to Harriet and the rest of the family at this very sad time.”
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