Former Labour chief whip Derek Foster has died in hospital in Sunderland, aged 81.
He was an MP from 1979 to 2005 before becoming Lord Foster of Bishop Auckland - the seat he had represented in the Commons.
Labour leader Jeremy Corbyn said Lord Foster, who was opposition chief whip from 1985 to 1995, had "served our party with distinction".
Mr Corbyn, a serial rebel while a backbencher, said: "As chief whip, he was always kind to me and supportive of new MPs.
"As someone obviously quite well known to the chief whip, I liked Derek very much.
"He served our party with distinction and we will miss him."
Lord Foster became the first ministerial resignation suffered by Tony Blair's government - just two days after being appointed in May 1997 - reportedly in protest at the junior role he had been given at the Cabinet Office.
The Labour whips office said Lord Foster died in hospital in Sunderland of secondary cancer.
Nick Brown, Labour's current chief whip, said: "As a Member of Parliament for Bishop Auckland, Derek Foster was the longest serving chief whip to the Parliamentary Labour Party in modern times, serving for 10 years.
"His shrewd judgment and fair-mindedness won the respect of his colleagues.
"He was passionate about the North East and in particular the jobs, pay and life chances of those living in the region.
"He was a lifelong campaigner for social justice.
"His wife Ann, family and friends are in our thoughts at this most sad time."