Corbyn has set out his Brexit plan and now he should begin his prime-minister-in-waiting tour of Europe

A few months ago, as part of an ongoing programme of cultural education, I bullied my teenage nephew into watching Trading Places. He clearly enjoyed the movie, because he checked his smartphone just the 179 times in two hours. But he wasn’t convinced by the premise about Dan Aykroyd’s commodities trader and Eddie Murphy’s street bum swapping lives. “It’s a bit far-fetched,” critiqued this Marvel Universe devotee. “Real life isn’t like that, is it?”

Real life may not be, but British politics apparently is. In the absence of two vile old brothers pulling the strings to settle a nature vs nurture dispute, it fell to Brexit to produce an unlikelier role reversal than the one in the film.

Days after being “revealed” as a secret agent run by the Czechs, Jeremy Corbyn is the toast of the CBI and the darling (within reason) of the FT. The terrifying red firebrand has been transformed into the business community’s chum. If he hasn’t been given honorary membership of the Rotary Club yet, it’s only a matter of time.

The Conservative Party has made the reverse journey. It has abandoned the pro-business pragmatism that defined it for centuries, and embraced the sort of hysterically rigid ideological purism often labelled as “Stalinist”.

Listening to Corbyn announce his belated customs union conversion, you needed the lowest dose of mescaline, if that, to picture him as a mid-1970s, one-nation Tory reasonabilist – bowler on head, brolly in arm – moaning about “more bloody strikes” to Reggie Perrin on the 8.17 to Sunshine Desserts.

JC didn’t get where he is today by being a pragmatic centrist. But when the facts change, and/ or the leathery aroma of the cabinet room hits his nostrils, he changes his mind. New Corbyn wouldn’t dream of sacrificing profitability and the jobs that depend on it on the altar of sacred principle.

He may privately dislike the European Union no less than ever, and isn’t about to launch Marxists For Globalisation. But he, unlike the Tories, understands economic reality too well to endanger service industries that count for four-fifths of the UK economy, or make every export batch of ball bearings to Slovenia a 92-form-filling nightmare. That he will leave to Boris, Gove, Dr Fox and others on the Government side.

On those benches, flanking a captive PM like idle undertakers inspecting a palliative care ward for their next cadaver, sit the New Soviets. In the Brezhnev era, Moscow would announce that the cotton returns from Uzbekistan had broken all records, when the entire harvest hadn’t stretched to a pair of knickers. As Fox’s former mandarin at the International Trade Department implies today, members of the Tory presidium are no less creative with their projections (the extra weekly £350m for the NHS).

Famously, the British electorate disdains ideologues who bend facts to fit quasi-religious belief systems, and almost invariably gives power to whichever of the main parties it perceives as the less extreme.

Admittedly, in 1945 the punters rejected Churchill’s bland continuity for Clement Attlee’s socialism, but only because they reckoned it more in their social and economic interests. And though Margaret Thatcher would challenge Clem for radicalism, she won in 1979 on a feeble unthreatening manifesto when Labour and the unions it represented were seen as the extremist option.

To many, Corbyn remains that, and always will. A headline above a Telegraph column on Monday ran: “Jeremy Corbyn’s Brexit shift shows he’s more determined than ever to seize power”. Note the subtle moulding of that “seize” into a makeshift synonym for “legitimately win an election”. In Telegraphland, seizing power is what Marxist dictators do in Africa and Latin America, even if, like Hugo Chavez, they are elected.

It seems too late for the reactionary press, try as it has and will, to embed Corbyn in the public consciousness as the love child of Chavez and Kim Philby. If demonising him as a commie sleeper didn’t do the trick at the last election, it won’t at the next when his rebranding as the grown-up voice of compromise has had time to take root.

But predicting a government’s collapse is a mug’s game, and the notion that Labour should turn Anna Soubry’s postponed customs union amendment into a confidence vote is misguided. Asking Soubry, Nicky Morgan and others to incinerate their careers by joining the opposition to bring down their own government would be counterproductive. Nothing unifies a schismatic party, however briefly and superficially, like a vote of no confidence.

Nonetheless, in this unparalleled volatility, the Government could abruptly fall for various reasons, perhaps the likeliest being the unsquareable circle of the soft Irish border fatally alienating the DUP.

So the suggestion to Corbyn is this. He should tour European capitals as prime minister-in-waiting, and dine with leaders of the EU and its largest states. It wouldn’t be as grandiose as Obama’s 2008 president-in-waiting tour, when millions thronged around the Brandenburg Gate. And it needn’t be a three-course dinner every night. A packet of crisps would suffice.

But quietly, soberly, with the reassuringly grown up Keir Starmer at his side, he should go to Berlin, Paris, Rome, Madrid and Brussels to meet those with whom he’d be parlaying if he wins, or seizes, power before March 2019.

He would be savaged for the measuring-the-No-10-curtains presumption. But he could easily swat that away by explaining that, given the time frame, it would be a dereliction of his duty not to prepare in case cutting the deal falls to him; that it’s essential to cultivate relationships with Tusk, Barnier, Macron, Merkel and the rest, and understand their thinking; that it would be a betrayal of British business to risk coming to the negotiating table ice cold a few months, or even weeks, before the exit date. That would be gravely irresponsible. And New Corbyn, CBI dreamboy of today and Rotarian of tomorrow, is anything but that.