Charles from Wakefield, who described himself as a life-long Labour voter, said Mr Miliband lacked credibility and was “unelectable”
He told Mr Miliband: “I don’t think people take you seriously. If Labour are going to win an election, it will be with someone else. “
He added: “You’re not going to be the Prime Minister of this country, by any stretch of the imagination and I’d put my life on that, that is not going to happen.”
Mr Miliband replied: “We’ll have to agree to disagree. I’m asking the questions that matter to people that matter around the country and I’ll keep doing that.”
Another caller, named as David, said Mr Miliband was putting people off the Labour Party.
“You fail to inspire, you fail to get people looking forward to getting out and getting the Labour vote out, it’s really bad what you’re doing, you’re not inspiring anyone, you’re making it hard for anyone to vote Labour."
“I don’t mean to be cruel, but it’s so important, the job that you have, and I don’t think you can do the job.”
Another caller, Gareth, referred to the Labour leader as “David Miliband”.
A fourth, named as Karen, highlighted Labour’s financial reliance on trade unions.
“His links with the unions are going to cause a problem getting middle class voters back,” she said.
Mr Miliband attempted to shrug off the criticism, but sometimes faltered in his attempts to disagree with his critics.
Later, he said: “That’s life. That’s what you come into this gig for.”
Mr Milband also said that he takes advice from former Labour leaders including Tony Blair.
“The advice he gives me is be yourself,” Mr Miliband said. “We don’t agree about everything but we agree on a lot.”
Asked if he took advice from Gordon Brown, Mr Miliband replied: “I talk to all the past leaders, but not that regularly.”