Shadow home secretary Yvette Cooper has accused Gordon Brown's former aide Damian McBride of being "out of control".
Cooper, whose husband Ed Balls was a key Brownite, told Sky News' Murnaghan programme: "I think this is ... about a kind of politics that really is appalling, that we should never go back to.
"It is something that happened some years ago, but I think it's a sign of how much the Labour Party has changed, the very different climate, the very different way in which Ed Miliband is managing things and operating things now, that's a good thing.
"We don't want to go back to the navel gazing of the past."
More top news
The full list of winners of the 89th Academy Awards in Hollywood.
The Oscars was plunged into chaos as La La land was mistakenly announced as the best picture, the actual winner was Moonlight.
The tourists had no idea they were about to be dropped off at the star-studded ceremony to meet A-listers.