IT would be funny if it were not so serious. The very idea Boris Johnson is “up for it,” making an improbable return to Number 10, should fill all of us with a sense of dread.

After his circus act of a premiership, followed by the Frankenstein experiment that was Liz Truss’s brief stay in Downing St, Britain is calling out for calm authority and political stability, qualities not associated with the “honking pudding,” as one Labour source affectionately described the ex-PM.

Nerves will be jangling strongly in Scotland, where Johnson’s return to Number 10 would result in many Conservatives screaming at the wall. Some fear that it would “risk the Union”. The ex-PM is rightly regarded as an electoral liability here, where, if he regained power, the Tories could face a wipe-out at the next General Election.

Jackie Baillie, Scottish Labour’s deputy leader, argued the notion the Tories were any longer the party of the Union was a “sham” and only Labour could now properly defend it against the SNP separatists.

As the Nationalist leadership put the party on election alert, Westminster leader Ian Blackford said, “given everything that happened” when Johnson was PM, it would be “beyond the pale” for him to return and “beyond belief” the Conservatives would even consider it.

Having secured his place on the ballot paper, gaining over 100 nominations, and poised, as I write, to enter the race, Sunak along with his backers are ringing round MPs this weekend to garner support and warn about the perils of a Johnson return in a “Stop Boris” campaign.

Michael Gove, who twice helped to quash his old Brexit colleague’s hopes, is said to be “on manoeuvres” at Westminster to ensure Johnson’s resurrection doesn’t happen.

Lord Hague, the ex-Conservative leader, summed up many Tories’ fears when he claimed the blond Beatle’s second coming would lead to his party’s “death spiral”.

Yet backers of Johnson make clear he won a public mandate in 2019, is a serial winner, “got Brexit done,” steered Britain through the worst of Covid with a pioneering vaccination programme and led the world in supporting Ukraine against Putin’s belligerence. Not only that, he is popular with many people; a politician who brings vigour and colour in an age of dull machine-politicians.

All of which is true. But a leader can only lead successfully if those around him feel they can trust him. What happened this year showed many of them don’t and couldn’t after he deceived them.

More than 60 ministers quit; an inconvenient fact Johnson supporters ignore or glide over as irrelevant.

Jacob Rees-Mogg, that pin-striped paragon of modernity, said it had been an “error” for Tory MPs to dump his fellow Old Etonian, explaining: “Boris Johnson’s attraction is he is a big, charismatic political figure, who is able to get things done and able to connect with voters in a way no other politician of this era can.”

There was talk yesterday of Johnsonites trying to broker a face-to-face meeting between their man and Sunak to end the inter-camp sniping. The fear must be it could let Penny Mordaunt, promising a “fresh start,” to come through the middle.

Some supporting the ex-PM have spoken of a “unity pact,” reforming the Downing St band; no doubt meaning Johnson would be back at the helm as he wouldn’t countenance being Sunak’s number 2.

The problem for the ex-Chancellor is if the 150,000-strong membership is again called on for its view, Johnson could pip him at the post; a recent poll among members gave the former PM a nine-point lead over Sunak.

And yet there are some right-wingers like Lord Frost, the ex-chief Brexit negotiator, who believe the party must “move on” from the “chaos and confusion” of the Johnson premiership and Sunak is the safer pair of hands.

At this time, however, given the Conservatives’ internal differences go so deep, it seems delusional to think any candidate could inspire the unity needed to win an election. A recuperative period in the sanatorium of opposition awaits.

The problem, of course, with Boris is - Boris. His character has a fundamental weakness; bolstering his ego is his primary instinct; everything else is secondary.

An early warning came in 1982 when Martin Hammond, the ex-PM’s classics teacher at Eton, wrote to Stanley Johnson, his father, remarking on 17-year-old Boris’s belief in his “effortless superiority” and how he should be free of the “network of obligation that binds everyone”. Partygate in a nutshell.

And if the North London MP returned to the Downing St hot-seat, his past would be present because of the ongoing Commons inquiry into whether or not he lied to the Commons over partygate, which could ultimately see him lose his seat in a forced by-election.

Dominic Raab, Johnson’s former deputy, described the parliamentary probe as a “fundamental hurdle” to his colleague’s attempt to seize back the Conservative crown.

The ex-DPM, a prominent Sunak supporter, insisted the party could “not go backwards,” adding: “We cannot have another episode of the Groundhog Day of the soap opera of partygate. We must get the country, the Government moving forward.”

If Johnson’s return were curtailed by the MPs’ probe, the markets would take fright and Britain’s economic problems would increase and our world-standing sink even lower.

Worryingly, economist Lord O’Neill said the changing of the UK’s economic outlook from “stable” to “negative” by Moody’s, the credit ratings agency, due to political instability and high inflation, was a “very clear warning if we make more errors, they will downgrade us, which will mean for some investors they won’t be technically or legally allowed to invest in the UK”.

To give an idea of international reaction to the prospect of Johnson making a return to power, the German newspaper Der Tagesspiegel had a front page picture of the ex-PM with a one-word headline: “Ernsthaft?” - “Seriously?”

The message to Conservative MPs this weekend is clear: for heaven’s sake, put the country first or the country will put you out.