Ed Balls has made his most public overture yet to Vince Cable, calling on the Lib Dem business secretary to "show leadership" and pull his party out of coalition and work with Labour.
"Right now, if the Lib Dems said, 'ok, we got this one wrong, and we’re walking out', I think that would absolutely be in the national interest," Balls said.
In an in depth two-part interview with The Huffington Post UK ahead of his speech to the Labour Party conference on Monday, the shadow chancellor said: "The Lib Dems have far more power to shape the destiny of this parliament than sometimes they realise.
"I don’t think there's any possibility of getting Clegg to change his mind but I think there is a chance of changing Vince Cable’s.
"He’s clearly willing to say to people off the record that he’s worried. I think he should come out and show a bit of leadership."
Balls' comments indicate that Labour would be willing to work with the Lib Dems on the condition that they ditched Clegg.
However on Sunday the Guardian reported that the Lib Dems would find it "intolerable" to work with Balls in government.
Cable recently admitted to occasionally exchanging text messages with Ed Miliband, even making a joke about it during his speech to the Lib Dem conference in Brighton.
And in a sign that Balls wants to keep the lines of communication open, he also gives the biggest hint of Labour's willingness to do a deal with the Lib Dems.
"I think there are some things that are far too important to allow to be made secondary to a narrow personal or party interest," he says.
"The jobs of young people and the future of our economy are things that require you to do the right thing and the idea that you would sort of turn away for sectional reasons from doing the right thing in a hung parliament would be absurd.”
Balls' courting of the Lib Dems, and Vince Cable in particular, is in stark contrast to the approach of Labour's deputy leader Harriet Harman, who has repeatedly hit out at the Lib Dems for being Tory "accomplices".
On Sunday morning, speaking after Balls spoke to HuffPost UK, Ed Miliband also said the Lib Dems were "an accomplice" to the Tories.
But in what appears to be a direct dig at Harman, Balls says: “Do we glory in our moral righteousness for the next two and a half more years while people continue to pay a price or do we say to decent people 'if you’re decent, do something about it'?”
In the interview with HuffPost UK, Balls also insists he will not apologise for Labour's spending record during its 13 years in office and claims the party is recovering its reputation for competence both with business leaders and voters.
“Step by step, month by month, we are closing the gap, we are making progress, but we still have a long way to go," he says.
Balls says that when he goes to see business leaders now, they say to each other "You can’t discount what he has to say”.
“I don’t think, to be honest, it was something which would have been said about Labour economic figures at any point in the 1980s.”
Balls also declares that he no longer "gives a toss" about becoming leader of the Labour Party one day, having failed to secure the job after Gordon Brown stepped down in 2010.
“I think its very unlikely and not motivational for me in the way that maybe it was 15 years ago, or maybe it is for others today," he says.
"If I’m honest for you, personally, it doesn’t matter, I actually don’t care, it' s not something which I think about, worry about, care about at all whether I’m leader of prime minister, it's not part of my mindset, it's not part of my goals.
"If I say to you I rule it out, I don’t think you’d believe me. If I say to you its very unlikely, I think that’s totally honest, I don’t care. I don’t give a toss. I really don’t give a toss.”
He adds: "If my political career ends today, this minute, I would look back on the last 20 years and I’d be happy with my obituary.”
However Balls is naturally not happy simply being shadow chancellor, and has his eyes set firmly on a return to the Treasury.
"If the pinnacle that I reach is to be chancellor in the next Labour government, that would be absolutely 100% for me."
Balls also has some advice for any lingering ambition David Miliband has to succeed his brother Ed as Labour leader.
"If I was giving David some advice, I would say he probably shouldn’t give a toss.”
Balls says he would 'back' Miliband if he wanted to return to the shadow cabinet but wouldn’t give up the shadow chancellorship for him, joking: "There’s a limit to even my generosity."
And as for Ed Miliband's leadership of the party?
"People aren’t asking the question yet: ‘Who should be the prime minister in two and a half years time?’ Therefore, compared to the guy who stands in Downing Street and does it every day, that is inevitably a comparison he can’t win."
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