The Labour Party is being run in a "totally dysfunctional" way with policies that amount to "a great steaming pile of fudge", according to a former party spin doctor.
In an apparent attack on Ed Miliband's leadership, Damian McBride warned that the party has a problem in communicating positive messages to voters and that its policies either do not stand up to scrutiny or "go unnoticed in the pub".
In an updated version of his memoirs, serialised in the Daily Mail, Mr McBride said Mr Miliband should position himself as an outsider like Boris Johnson or Nigel Farage rather than an establishment politician directed by PR advisers.
Mr McBride, who was forced to resign as former prime minister Gordon Brown's adviser in 2009 after being linked to a plot to smear Tory MPs on a gossip website, said: "Labour currently has no clear idea who its target audience is, no positive messages to communicate to anyone about why they should vote for the party, no policies which will persuade them, and is being run in a totally dysfunctional way."
Mr McBride also criticised Mr Miliband's team for attempting to boost the leader's public image through photo opportunities.
But his comments could be viewed as an endorsement of a change of tack by Mr Miliband, who used a risky speech last week to admit he is not good at photo opportunities, claiming he was a politician of substance.
Mr McBride wrote: "Ed's advisers will tell him to be pictured doing the everyday things that normal people do to show he's not 'weird'; they'll arrange opportunities for him to look all serious and statesmanlike to counter the perception that he's not prime minister material; and conversely, they'll urge him to crack jokes with Graham Norton or shed tears with Piers Morgan so that we can all begin to see the 'real Ed'.
"This will all be a colossal mistake. Not just because it leads to bad photos with bacon sandwiches, but because the blatant artifice of the whole effort risks throwing away the most important commodity any successful modern politician must possess: authenticity."
The former spin doctor urged Labour to acknowledge its mistakes in government and to better communicate a coherent plan for the country.
He wrote: "If Labour currently has central, underlying messages that it is trying to communicate to the electorate about itself, its policies, and its leader, the best you could say at present is that it's not quite coming across.
"If the message is 'We're not the Tories or the Lib Dems, and you hate them', that may work up to a point, but it won't do much for those people who would happily express their antipathy by voting for Ukip or just staying at home, let alone those who hate Labour as well.
"Even the 'cost of living' argument - for which read 'Those Tory toffs haven't got a clue what your life's like' - relies on the electorate accepting that Labour has some better appreciation of those realities."
Mr McBride's book, Power Trip, threatened to overshadow last year's Labour Party conference with its expose of toxic internal feuding during the New Labour years.
His comments on Labour's current situation are published in an updated paperback edition of the book.