Ed Balls has branded Labour beliefs that engaging the disadvantaged, dispossessed and disillusioned alone will secure election victory "utter deluded garbage".
The former shadow chancellor described his "guilt" of being left to watch the fight over Brexit from the sidelines, his voice diminished as Britain faces "massive issues" while he dances the cha cha.
Still feeling the pain of his humiliating defeat to the Conservatives last year, the ex-MP-turned Strictly Come Dancing star urged Jeremy Corbyn to charm those same Tory voters, gather Parliamentary support away from the capital's left and overcome squeamishness over immigration.
He made the comments to The Times while eating a lunch of tofu and spring rolls during a break from rehearsals at an east London dance studio.
"The thing that shocks me is when I say we can't win the election unless we can persuade people who voted Tory in 2015 to vote Labour again, there is a reaction from some Corbyn supporters which is, 'we don't want anybody who voted Tory to vote for us'," he told the newspaper.
"They believe there is enough people in the non-voters and the disadvantaged and dispossessed to somehow make this outsider coalition big enough. It's utter deluded garbage."
Mr Balls said Labour's chances of avoiding a fourth successive electoral defeat will only come about if their leader "speaks to the voters".
"That means he can't just have conversations with London left-wing MPs. That's his choice now. But if you say that talking about controlling immigration is racist then you have no possibility of a conversation with most people living in our country who should vote Labour."
After winning the recent leadership election Mr Corbyn welcomed back 10 MPs who resigned during a mass exodus from his shadow cabinet in the wake of the EU referendum.
However, as reports emerged of a "shadow shadow cabinet" organising in secret, Keir Starmer, the shadow business secretary, said issues in the party remained "unresolved".
On Thursday the incumbent shadow chancellor said Labour would not make "cynical" promises on cutting immigration and accused the Conservatives of knowing their targets on numbers and timescale will be missed.
"It is not migrants to blame for low pay and insecurity at work, or the high cost of housing, it is the failure of our whole economic model," John McDonnell said.
Mr Balls revealed how he had to leave the country as a triumphant George Osborne delivered the first budget after the general election and said visiting his old constituency of Morely and Outwood in West Yorkshire remains "very difficult".
He said: "The truth is I feel guilty. And I can't do anything about it at the moment because I'm not an MP.
"The country's got massive issues to face and I'm doing the cha cha? I do feel a bit of angst and guilt about it. Is there something I could be doing to make things better? But you have to know when your time is. And maybe now is not my time."
Yet despite weekly drubbings by the dance floor judges Mr Balls appears to be upbeat when his focus is strictly ballroom. "I've discovered that I have this camp sense of fun, which I never realised," he told the newspaper.
He even suggested Mr Osborne, now relegated to the back benches should consider signing up for next season, but the response was "absolutely" not, Mr Balls told The Times.