Ed Miliband said he was taking Tony Blair's advice to "be yourself" as he brushed off severe criticism of his leadership from radio listeners.
The Labour leader said he was neither frustrated nor affected by attacks on his performance and insisted he remained "optimistic and confident" of general election victory.
Mr Miliband was confronted by a string of negative personal assessments from people who identified themselves as Labour voters during a phone-in on BBC Radio 5 Live.
Among the critics, two said he should step aside if the party was to have any chance of taking back power when the country next votes in 2015.
At one point his line to the studio failed and he was surprised to return to the airwaves midway through one lifelong Labour supporter's complaint that he was an unelectable "laughing stock".
While fears were not "trivial", he said, they were the sort of barbs endured by all party leaders - adding that he had sought the advice of predecessors such as Mr Blair on a number of occasions.
"We will have to agree to disagree," he said of his on-air critics.
"I go around the country and I talks to lots and lots of people about how we can change their lives. That's what I came into politics for and that's what I think the Labour Party's about.
"People will make their own judgments.
He added: "I won't say it's trivial but, no, I am not affected, because you come into this job knowing that you get lots of commentary, lots of criticism.
"That's life. That's what you come into this gig for. What matters to me is the people I meet and the issues that I talk about."
He said Gordon Brown and Mr Blair were "always good sources of advice" when he sought their opinion - in particular over dealing with prime minister's questions.
"The advice he (Blair) gives me is 'be yourself'. He does not agree with me about everything but we agree on a lot. I've said I think we need to move on from New Labour.
"When I speak out about something like bank bonuses or Rupert Murdoch, it's because I see what's wrong and I speak out about it. That's the way you've got to do the job."
Responding to criticism of his performance in the weekly Commons confrontation with Prime Minister David Cameron, he said: "I try to ask the questions I think the country wants asked.
"Sometimes you win at Prime Minister's Questions, sometimes you don't.
"But what's really important is to ask ... the questions that matter to people round the country and I am going to keep doing that."
Dismissing the Opposition's failure to open up consistent leads in opinion polls, he said: "It takes time for parties to recover."
Asked if it could happen by 2015, he said: "Yes, of course. But the thing you have to do as a politician is not watch the polls; what you've got to do is do the right thing.
"By the next election we will show that we can make a difference to people's lives and we do have the right priorities for people.
"I am optimistic and confident ... but you never take the British people for granted."
The listener who was venting his frustration as the party leader returned to the airwaves, who said he was a lifelong Labour voter from Wakefield, told him: "It is quite clear to everybody that you are not going to be the prime minister of this country by any stretch of the imagination.
"If Labour are going to win the election it will be with somebody else. Someone like Peter Hain, who has a wealth of experience of life."
Mr Miliband joked that he would pass on the compliment to the shadow Welsh secretary.