If you believe David Miliband has the answer for Labour, the question is: what's wrong with you?

After a self-imposed exile in New York, the threadbare sock puppet of Blairism, David Miliband, has made a pronouncement. As always, David’s linguistic stylings suggest a cybernetic prototype suffering with malfunctioning circuitry, so good luck to the boys and girls at Bletchley there. But since he finally sees fit to lob his grenade into the Labour leadership debate – and since his underlying intent is clear – courtesy demands we pay him the attention he regally assumes is his due.

In fact, we have little choice. Tempting as it is to imagine him vanishing from the domestic political scene, it isn’t going to happen. When David left us for International Rescue, he did not detonate his ambition with the same nuclear sulkiness with which he abandoned the brother, party and country he says he loves. He could have stayed. He could have sublimated that melodramatic sense of entitlement denied. He could have summoned the gumption to accept that his duty lay in devoting what passes for his talents to his party, and accepted his brother's offer of the shadow chancellorship. He could have shown that with him, as with any mature politician, serving the common good outranks indulging hurt feelings.

Instead, this posturing princeling of peevishness scarpered to his own Elba on America’s east coast, whence to sneer at his brother – and later to celebrate his electoral humiliation – and glance longingly out to sea and daydream of one day returning in triumph. Whether he will turn out to be Napoleon or Bonnie Prince Charlie, his allies are already machinating for a restoration. In his Guardian article, tellingly, David gives a shout-out to the two leaders of this cause. “I have been struck... by the plain speaking, fresh thinking and political courage of Liz Kendall,” he writes, before citing her (and his) supporters Chuka Umunna and Tristram Hunt as also impressive. Coincidentally, Messrs Hunt and Umunna last week unveiled Labour for the Common Good, an embryonic outfit some apparently regard as “the resistance”. But since even the most hysterical uber-Blairite might balk at comparing Jeremy Corbyn to the Nazis, and with no Charles de Gaulle manqué visible at the helm of this scintillating new group, feel free to presume that its true purpose is to plot for the day David Miliband returns to the Commons and ousts Corbyn.

That is their right. It is slightly unusual to scheme against a leader before his election, but the members of a party are entitled to try to remove a leader, just as a leader is entitled to fight to prevent them from succeeding. So the first thing Corbyn should do – if and when elected – is finesse Labour’s National Executive Committee to change the rules to ensure that it is the membership, and not the MPs, who spark a leadership challenge.

This, as fervent democrats such as Tony Blair, Alastair Campbell, Peter Mandelson and, indeed, David Miliband must agree, is the democratic way. If Labour is anything, it is for the many, not the few.

But even if Corbyn were swiftly removed, would David Miliband be the right guy to replace him? The problem with David Miliband, apart from having the verbal clarity of Professor Stanley Unwin, is cowardice. I say that in a very caring way, because this quality is doubtless genetic. Ed Miliband, whatever his failings, inherited bravery in spades. David, bless his fluttery heart, did not.

Psychoanalysts will note that, in his praise for Kendall, David cites the very three qualities he so desperately lacks.

“Plain speaking” is so beyond him that he could spend 17 minutes asking a hardware shop assistant for a hammer, and leave the store with a corkscrew, two dozen Phillips screwdrivers and a power drill.

In his bespoke lexicon of political cliche, meanwhile, “fresh thinking” translates to “barely rehashed Blairite ideas which sounded stale a decade ago”.

As for “political courage”, where in the name of sanity do you begin? In the summer of 2008, when, in an earlier Guardian tour de force, David made a coded challenge to Gordon Brown’s authority days before a) posing with a fruit colour-coded to highlight the yellow streak running through him, and b) scuttling off into the undergrowth when Gordon announced it was no time for a novice? Or a year later, when his bestie James Purnell quit the Cabinet to pave his way to resign and defenestrate Gordon Brown?

Even with the ball on the spot and the one-eyed goalie lying concussed by a post, David couldn’t even manage to take the kick.

Or when he made his drearily narcissistic flight to New York, too enfeebled to conquer wounded pride in the cause of that sacred common good?

Liz Kendall tells us she has “lady balls” – and so, unutterably hopeless candidate though she is, she has. David, like Goebbels in the wartime ditty about the Fuhrer’s alleged testicular shortfall, has no balls at all. And balls of whatever gender are the one prerequisite, we can surely agree, for leading the Labour party in the years ahead.

To anyone who believes that David Miliband is the answer, the question, borrowing from the great Dawn Butler to Sky News’ resident eighth wit Kay Burley, is this: What. Is. Wrong. With. You?

In his arrogance, Miliband misunderstands Corbyn’s populist candidacy as predicated on “angry defiance”, when it is unmistakably built on hope. This is classic projection; all the anger (about their own impotence) and defiance (of their own irrelevance) lie with the pitiful clique of Blairites scurrying around questioning the wits and motives of the majority who tired long ago of their imperious contempt for any beliefs but their own.

David Miliband can stay as angry and defiant as he likes while he surveys the carnage on the battlefield he fled from his cosy berth 3,000 miles away. But it wouldn’t half be nice if he spontaneously developed the self-awareness to appreciate that the only decent way to do this is in the absolute silence that would spare us all the misery of trying to decrypt his words.