Voters "don't see" Ed Miliband as a prime minister and Labour will struggle to achieve an outright victory in next year's general election, one of the party's senior MPs has conceded.
Former Cabinet minister Peter Hain said Mr Miliband was "likely" to be in No 10 after the 2015 election, but it was "very hard" for the party to win a majority.
Meanwhile senior frontbenchers acknowledged concerns about the rise of Nigel Farage's Ukip, which made inroads into some of the Labour Party's traditional support at last month's elections.
Mr Hain, who is standing down at the next election, told Sky News that voters would realise that Mr Miliband was the right person to lead the country once he was in Downing Street "even if maybe they don't see that at the moment".
The Neath MP said: "Whether we'll have a majority, which I will fight for along with every other Labour Party member, I don't know because it's very, very hard to win a majority now in British politics because we're not in a two-party system, which we had for generations. We're in a multi-party system."
He added: "I think that Ed Miliband is well placed to lead the government in the future and I think people, when they see him as prime minister, will actually realise that they've elected the right person even if maybe they don't see that at the moment."
Concerns about the loss of Labour's core support to Ukip were raised by shadow work and pensions secretary Rachel Reeves on the day of the Newark by-election, according to reports.
The Mail on Sunday reported that she told the event at Queen Mary University of London: "Our very raison d'etre will be threatened if the working people, who the Labour Party have got to be there for, and got to be a voice for, start to drift away because they don't see us as the answer."
She said traditional Labour voters " who perhaps at times we took for granted but had nowhere else to go are now being offered an alternative by Ukip".
Shadow education secretary Tristram Hunt said Ms Reeves was echoing the message given by Mr Miliband " that we have to make sure that those communities who we historically represent regard Labour as having a successful message for them".
Asked if he thought Ms Reeves was right, he told BBC1's Sunday Politics: " If we have got more work to do to get people to the polling booths, then absolutely. Rachel Reeves speaks with great authority and wisdom and we should always listen to what she says."
Shadow home secretary Yvette Cooper said there were "legitimate concerns" about immigration but "Ukip have been playing on people's fears and exploiting people's fears".
She told BBC1's Andrew Marr Show: "We can't imitate Ukip, we have got to take them on."
On BBC Radio 5 Live's Pienaar's Politics, she added: "I think that what Ed's done since the election has been immensely important, both in terms of uniting the Labour Party, in setting out the policies that helped us win 300 more councillors in the local elections, whether that's from the energy price freeze to building more homes and so on.
"We are all working together, we are working with Ed in order to keep campaigning."
Labour distanced itself from a leaked document on the future of high streets commissioned by the party, which the Mail on Sunday reported was recommending a range of new taxes to fund regeneration.
All shop owners would be forced to pay a new property owner's tax separate from existing business rates, firms in prosperous areas of England would face a new business tax to fund handouts in poorer areas and farmers would lose a tax break, the newspaper said.
But a Labour spokesman said the leaked document, by former Wickes boss Bill Grimsey was "not a Labour Party report or Labour Party policy".
"A future Labour government would cut business rates for small businesses," the spokesman said.
Mr Grimsey said "nothing has been proposed yet" and the "Labour Party has not seen any work yet".