With a few exceptions, the dark briefings by ministers against other ministers within Labour went away with the departure from No 10 of Tony Blair, who gave a speech today backing his old rival Gordon Brown. But then they started up again against Alistair Darling, whom Brown wanted to replace as Chancellor with Ed Balls, as I outlined last week. Now, there is a new victim of these mysterious and -- for Labour -- counterproductive whispers: Ed Miliband.

Although Miliband is highly popular in Labour and seen (somewhat reluctantly) as a future leader, he is not, on the whole, resented by his colleagues for that, and is running an inclusive manifesto operation, on which I reported recently. Most cabinet ministers say they have full confidence in him and his team when it comes to writing the manifesto; they are relieved that it is in their hands.

So it is curious that Miliband is suddenly the victim of negative briefing in the Financial Times. The FT is a highly credible paper, so we can be sure that its reporters genuinely spoke to a "senior" minister. From a report today:

Ed Miliband's claim to be putting the finishing touches to Labour's most radical ever election manifesto has caused concern among ministers, who fear he has oversold a document that draws heavily on familiar party policy and is tightly constrained by the fiscal crisis.

Mr Miliband was charged by Gordon Brown, the Prime Minister, with drafting the Labour manifesto three years ago. Some parts of the document have survived intact since the party's abortive "non-election" campaign in 2007.

Other policies -- including a commitment to House of Lords reform and changing the voting system -- are relics of Tony Blair's 1997 programme that were never fully implemented.

Several senior ministers have criticised Mr Miliband over an interview he gave to the Guardian last week, in which he trailed parts of the manifesto. Among his promises [was] the creation of a "People's Bank" to help provide banking services to all parts of the community, based around the Post Office network.

Yesterday, Lord Mandelson, the Business Secretary, announced £180m of new funding for the Post Office, as it launched a new current account and first-time buyers' mortgage.

In the Guardian interview Mr Miliband agreed the manifesto was Labour's most radical yet. One minister regarded the interview as "surprising" and another believed it was "a disaster".

Mr Miliband also proposed capping the rates of interest charged on loans, raising the national minimum wage and offering free school meals for all children. New Labour elements in the party regard all these policies as evidence of Mr Miliband's supposedly traditional "lefty" approach.

The criticism of Mr Miliband has bemused the Energy Secretary and may stem from a suspicion by colleagues that he is trying to turn Labour's manifesto into a personal manifesto for a future leadership bid.

Hmm. Quite apart from the bizarre notion that the manifesto could be too radical when the stakes are so high, Miliband is known among his friends not to be thinking about the leadership. He winces at the very mention of it (scroll down from this link), may well not run against his elder brother, David, and is 100 per cent focused on the manifesto as well as his climate-change and energy brief.

Could it be, instead, that these rather weird briefings are coming from someone else with his eye on "a future leadership bid"? Some are speculating that they could be coming from the highly ambitious Schools Secretary, who is not averse to putting himself before his colleagues occasionally.

Surely, this is far-fetched: Eds Miliband and Balls are old friends, and doubtless the latter wants the party to be united going into this crucial election.

Let's hope and assume so.