Ed Miliband ally Lucy Powell tells unnamed Labour critics to put up or shut up

But fellow Shadow Cabinet minister Caroline Flint admitted some Labour MPs were 'having jitters'

Lucy Powell, left and Ed Millband. Only 34 per cent of Labour voters think Ed Miliband is up to the job of Prime Minister

(Rex/AFP/Getty)

Labour is facing a battle to convince voters that Ed Miliband has the “leadership qualities” to head his own party “let alone the country”, one of his closest allies warned on Sunday.

Lucy Powell, who was promoted in last week’s reshuffle to help run Labour’s election campaign, admitted the party had been damaged by the recent unrest over Mr Miliband’s leadership.

A poll on Sunday showed that only 34 per cent of people who voted Labour at the last election believe Mr Miliband is up to the job of Prime Minister – compared to 51 per cent a year ago.

Speaking on Radio Five Live Ms Powell, who used to work in the Labour leader’s office, urged Mr Miliband’s so far anonymous critics to “show us your colours and put names to quotes” or else allow the party to get back to its campaigning message.

“When you have continuing stories being floated around that Ed has lost the confidence of his MPs, that obviously feeds a wider concern in the public about whether he’s got the leadership qualities to lead his own party, let alone the country,” she said.

“The worst of all worlds, as we come to the general election, is for me and other colleagues to be having to have this conversation all the time,” she said.

However, another of Mr Miliband’s Shadow Cabinet ministers Caroline Flint admitted that some Labour MPs were “having jitters” as the polls became tighter.

“Look, some of my colleagues are having jitters and part of that is that we’ve always said that this is not a done deal,” she said.

“But also all of us in the party... have to go and hold our heads up and fight for the right to be elected. And that’s the noise we need to make, not some of the noises off from unattributed individuals over the past few days.”

Labour spokesmen have for several days been dismissing claims of a leadership crisis as overblown and insubstantial.

But while no senior MP has come forward to openly criticise Mr Miliband, a number have been privately highly critical – even if they think the chances of removing him before the election are slim to non-existent.

One said: “I don’t know a single person who thinks we can win the election under Ed. It’s very depressing.”

A source close to Mr Miliband admitted there were “a few” people who were “unhappy” and deliberately briefing newspapers but suggested they were far fewer in number than those Conservative MPs unhappy with David Cameron’s leadership.