Tom Watson has said he stood down as Labour’s deputy leader and from Parliament because of “brutality and hostility” within the party.
The former West Bromwich East MP, who stood down last month, told the Guardian criticism from factions and on social media became a “heavy load”.
Mr Watson also claimed party officials concealed a death threat towards him.
The 52-year-old, who has lost eight stone in weight, is retraining as a gym instructor.
Speaking to the Guardian’s Weekend magazine in the wake of Labour’s election defeat on 12 December, Mr Watson said of his decision to stand down: “The point is that the brutality and hostility is real and it’s day to day.
“So I just thought: now’s the time to take a leap, do something different. You’ve had a good innings. You’ve done good stuff. Go now.”
Mr Watson also used the interview to praise outgoing leader Jeremy Corbyn personally, but admitted voting for rival Owen Smith during the party’s 2016 leadership election.
The party is now preparing for a fresh leadership race in the wake of the recent election result.
West Bromwich East was gained by the Conservatives for the first time with a majority of 1,593.