She told Nandy: “Lisa, for God’s sake love, do something about it and get in there and if it’s not going to be you back someone else.”
The appeal came at the conclusion of an impassioned speech for Nandy, a former shadow cabinet member, and MP for Wigan, to begin a leadership challenge.
Davidson said: “Today, Jeremy Corbyn has been in office about eighteen months.
“Eighteen months into Ed Miliband’s leadership, the Labour party was polling 44 percent and it was ten percent ahead of the Tories, and it went on to lose the next election.
“Today, the Labour party is polling at 26 percent, this is eighteen points behind the Tory party. That’s the size of the drop off that there’s been in Labour.”
Unite general secretary candidate, and fervent Corbyn supporter, Len McClusky intervened, saying: “Because of division.”
But Davidson snapped back: “It’s because of lack of leadership. As a Tory you might think I love this, but I don’t. Yes, I’m a Tory but I’m a democrat.
“I think the Labour party is doing a disservice to itself by keeping Jeremy Corbyn in place, it’s a disservice to our country and our democracy because our democracy relies on the idea that should a government fall there’s a government in waiting ready to go and to make sure we walk a line.
Lisa, for God's sake love, do something about it and get in there and if it's not going to be you back someone else.
“Every week I hear a new coming person in the Labour party who is going to be the next leader whether it’s Rebecca Long-Bailey or Clive Lewis, or whether its Lisa Nandy
“Lisa, for God’s sake love, do something about and get in there and if it’s not going to be you back someone else.
Nandy replied: “That is the sort of ringing endorsement I need like a hole in the head.”
Watch the clip, above.
The moment drew applause from the audience and plenty of reaction from viewers at home - though not all positive.
Nandy, who left the shadow cabinet last year, has previously told HuffPost of her view that collective leadership is more important than one individual.
The 37-year-old has been tipped for the top job and has stopped short of ruling out a possible future run for leader.
Panelists on Thursday’s show came from Carlisle. Presenter David Dimbleby was also joined by Unite union boss Len McCluskey and Kate Andrews of the Institute of Economic Affairs.