Reshuffles come and reshuffles go, and Ed Miliband's afternoon of the short spoons came and went with such minimal impact that it barely deserves the title at all. If the dealer shuffled in such dilatory fashion at a Vegas poker table, you'd assume the game was rigged and head to another casino.

Little Ed can be excused for doing no more than tweak a few of his obscurati (not that the shadow Welsh Secretary isn't pivotal). With the latest poll showing Labour ahead by 14 per cent, why try to fix something that apparently ain't broke? For all that, I think he is missing a trick by leaving a potential ace buried in the deck, and suggest he brings it to the top of the deck in the more electrifying reshuffle he is expected to announce in time for the autumnal conference season. Ed Miliband needs somehow to make Alistair Darling his Shadow Chancellor.

The objections to this latest outbreak of fantasy politics are very obvious. For one thing, there is no evidence that the former Chancellor is any keener on swapping the safety of trenches for the front line than his great-great uncle Kevin at the end of Blackadder Goes Forth. The enemy may be less scary than the Bosch of 1918, with George Osborne wounded, perhaps fatally, by the double dip and his role in exposing the Conservatives to the full toxicity of the scandal which led to certain criminal charges yesterday. Even so, having served in the Cabinet throughout New Labour's 13 years in power, and stared into the face of financial armageddon after the 2008 collapse of RBS, Mr Darling may still be suffering from residual shell shock.

It would look like insanity, meanwhile, for Little Ed to risk the ceasefire which has unexpectedly settled over his party by humiliating the incumbent. Even his critics will acknowledge that Ed Balls has owned Mr Osborne in recent weeks. Moving him to a less lustrous portfolio, or more likely having to sack him for refusing one, would be sensationally incendiary. It would put the ice-pixie Yvette Cooper in a horrible nuptial position, and threaten to destabilise the party when stability is such a potent weapon of contrast against an ever more schismatic Coalition.

Having listed the gloomier aspects to this meisterplan, I now invite you to join me in its sun-drenched uplands. If ever a politician was exquisitely suited to a particular job at a specific moment, it is Mr Darling today. He has in abundance the quality that neither of the Eds, David Cameron, Mr Osborne nor Nick Clegg has at all. He has experience of successfully coping with a desperately sick economy and with the threat of imminent financial catastrophe that will revive if and when Greece leaves the euro. That alone makes him a potentially priceless asset.

The punters trust him partly on instinct because he seems so reassuringly dull (despite a wry wit that must make him good company); but primarily because, as Chancellor, he would not be bullied into silence, or outright lying, about the extent of the crisis. Messrs Brown and Balls had their trolls brief so savagely against him that, when he fell curiously silent during one particularly tense week, he was widely believed to be propping up a ring road flyover on the outskirts of Doncaster. Yet this deceptively tough chap would not allow them to bury him alive, and continued to break the first iron law of New Labour by telling the simple truth.

In a succession of cabinets peopled by fools, rogues, braggarts, incompetents, internecine plotters, pathological liars and messianic monsters, he shone out as a beacon of calm integrity and old-fashioned decency. He worked with the Blairites, and was close to Gordon, until almost the end, without ever becoming his creature.

The same may not be said of Mr Balls, who is too indelibly stained as Gordon's fellow arsonist, in preparing the inferno by relaxing fiscal discipline, to benefit fully from being proved correct about the best road to recovery. He remains a liability, for all his intellect and energy, because whenever the Treasury releases bad news, that cheeky little face cannot disguise relish at the impact on his career prospects. With every fresh negative growth or rising unemployment figure, one imagines Mr Balls doing a victory jig around the kitchen, clad only in his pinny, while preparing the lasagne. Mr Darling you can only picture sighing with empathy.

This is not the time for grandstanding opportunists. This is a time for solemn maturity, and for all his considerable talents Ed Miliband has not an iota of that. When the smart politician identifies a personal deficit, he imports the commodity. In our increasingly presidential politics he needs to balance the ticket, just as Barack Obama did by picking Joe Biden, to diminish the perception of being callow and what the Americans call unseasoned.

Speaking of wise old Nestors, isn't it lovely to see Peter Mandelson (and Mr Tony himself) returning to the fold just as Labour takes the ascendancy? This eerie coincidence of timing reminds us how Mandy did such damage to Mr Osborne after the yachtocratic pow-wows on Corfu, when some advised Cameron to replace him with a well-liked and trusted former Chancellor who, like Mr Darling, bequeathed an economy in growth. Had Cameron listened and made Ken Clarke Shadow Chancellor in 2008, hindsight suggests that his comforting presence would have inflated a plurality of seats into an outright Tory majority.

Whatever the longer term effect of Alistair Darling returning to shadow his old job, it would cement Labour's improbably large polling lead, while jettisoning Mr Balls would reinforce Little Ed's reputation for being a bold and effective gambler, built on his fratricidal seizing of the crown. Whether Milibandroid the Elder ever makes any kind of comeback may have symbolic importance, but in this game the most crucial step towards checkmating the Tories would come in the classic chessboard colour combination of white hair and black eyebrows.

This is purest fantasy politics, as I said, but outlandish fantasies come true every now and then as Sergio Aguero confirmed deep into added time on Sunday. So the final word to Labour's leader is this. Go to Alistair on both knees, and serenade him with the snatch of McCartneyist-Lennonist dogma pithily expressed by the Beatles in the fourth track on Abbey Road. "Oh Darling, if you leave me, I'll never make it alone/ Believe me when I beg you, don't ever leave me alone."