Almost half of UK voters think that the Labour Party would be better off at the 2015 General Election if they ditched Ed Miliband as leader, according to a poll from YouGov for LBC Radio.
The study found that 49% of respondents thought that scrapping Miliband, who has led the party since 2010, would be a good move.
The poll comes amid reports that Labour MPs are split over Miliband's leadership and backbenchers are circulating a letter calling on him to resign.
But Ed Balls said that the rumours were "nonsense" and claimed that Labour would "stay united" behind Miliband.
"I think this is all nonsense, to be honest. I've no idea about any of this," Balls told BBC News.
"All I know is that everybody in the Labour party, from Miliband down, is focused on tackling the cost of living crisis, building an economy which works for working people, reforming Europe but not walking away, getting tough and fair controls on immigration, saving our national health service – that's what Labour's for.
"It's the Conservative Party which are riven and divided and defecting, left, right and centre. Labour will stay united."
The latest YouGov poll for The Sun gives the party a one point leader over the Conservatives (33% vs 32%) ahead of the 2015 General Election next may.
The research also revealed that 15% of respondents would vote for Ukip and 8% would vote for the Liberal Democrats if an election was held tomorrow.