WE’VE not been here before. Boris Johnson may have lied, u-turned and dissembled his way through 29 months in the top job, but he’s never looked vulnerable – until now.

The backbench support and poll ratings that have cocooned him through one scandal after another are melting in the heat of public anger.

Three snap surveys show a majority of voters believe the Prime Minister should resign over the Downing Street Christmas party. Labour, for the first time, are four points ahead in the polls. Google searches for “cancel Conservative party membership” have spiked. Tory backbenchers who were once cheerleaders for Boris Johnson are in revolt. There is open talk of no-confidence votes.

This stink comes at the end of an extraordinary five-week period even by the standards of this shower, during which the government has stumbled from scandal to failure to humiliation. Sleaze, the scandalous death of migrants, that speech to the CBI, the Afghanistan evacuation and now this – and they are just the stories that fit on the front page.

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In the last 24 hours, it’s been a struggle to keep up: three Christmas parties are now to be investigated and the Prime Minister stands accused of yet more lying after it emerged he WhatsApped Tory peer Lord Brownlow for more cash to refurbish his flat, after telling a previous inquiry that he didn’t know who the donor was.

The dishonesty has become routine. If Larry the Downing Street cat revealed a secret recording of the cabinet playing spin the bottle last Christmas Eve, we would barely raise an eyebrow.

On the face of it, this is an early Christmas present for the SNP and toe-curling for the Scottish Tories. Ian Blackford, Nicola Sturgeon’s Westminster lieutenant, spoke for many when he stood up in front of a packed House of Commons and issued a thundering call for Mr Johnson’s resignation.

The benighted Scottish Tory leader Douglas Ross, meanwhile, has taken the pained position that he still has confidence in the Prime Minister but that Mr Johnson should resign if it turns out he misled parliament.

Nicola Sturgeon did not let it lie at Holyrood yesterday, and called again for Mr Johnson to go, as SNP MSPs jeered.

But the truth is that strategically, Boris Johnson leaving office would be the worst possible outcome for the SNP and the best thing that could happen to the Scottish Tories.

With the SNP’s case for independence from a post-Brexit UK snagging on economic and practical grounds, it’s the push factor of Boris Johnson’s woeful leadership contrasting with Nicola Sturgeon’s more competent management, that has helped propel Yes to new highs in the past two years, as Prof Sir John Curtice has pointed out.

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No other Tory leader could offer such advantages to the SNP – certainly not Rishi Sunak, Mr Johnson’s most likely replacement, who in September had a positive approval rating in Scotland of +3, vastly better than Boris Johnson’s -38 and not too far behind Nicola Sturgeon’s +14.

For Douglas Ross, on the other hand, a new Prime Minister is at the top of his Christmas list.

Naturally, having a Tory in Downing Street – any Tory – will ensure many Scots back independence, but the frontrunners to replace him – Sunak, Hunt, even Truss – would all be less offensive to Scottish voters.

Of course the SNP must push publicly for Boris Johnson’s resignation, and for the good of the country he should certainly go, but SNP strategists may have more mixed feelings in private.

Even if Ms Sturgeon could guarantee holding a referendum this parliament, support for independence is far too volatile for comfort, even on a good day. Ten days ago, one survey registered support for Yes at 55 per cent, triggering the usual fevered excitement from SNP figures, but seven other polls since September have put No ahead.

Ms Sturgeon’s approval ratings have deflated since she stopped being on the telly every day and are now half what they were this time last year (though she remains Scotland’s most popular political leader).

Could an independence referendum be won without Boris Johnson in Downing Street? Yes, but the economic case will have to be even more convincing and the Scottish Government will have to try even harder to convince voters they are competent stewards of public services. It’s so much easier to present Boris Johnson as the embodiment of all that’s wrong with the UK government.

So how likely is it that Boris Johnson will be forced out? It’s not imminent. Libertarian Tories are all in a froth about new Covid measures, bleating on about mask-wearing and working from home, but Labour looks set to vote through the measures in England, ensuring the government prevails next week.

The cabinet secretary’s inquiry into the Downing Street parties reeks of expediency, hurriedly ordered by Mr Johnson to pre-empt a storm at Prime Minister’s Questions (much good it did him).

Yes, it could end Mr Johnson’s premiership, in theory, but he’s already made clear he intends to make his staff take the blame and he has a knack of getting his way. As Matthew Parris memorably put it on BBC Newsnight: “[Boris Johnson] has come into a bit of a tangle with a good many people in his career. Someone has always come off worst and it’s never him.”

But if there are further revelations about these and a host of other lockdown-breaking parties – claims have so far been made of seven, including one in the Prime Minister’s own flat – the strategy will fall apart.

Clearly it would be daft to rule out yet another completely unrelated scandal erupting over the next few days, on the showing of the last month.

And all the while in the background, there’s the wider malaise out there in the country to be considered. A “levelling up white paper” has been delayed, inflation is rising, wages are being squeezed, the NHS is underfunded, Universal Credit has been cut and Brexit is a hopeless mess, as the economy falters while Britain petulantly demands satisfaction over the Northern Ireland protocol it signed.

So Johnson’s definitely not safe. If Tory MPs do decide to press the eject button on their leader, they’ll want to do it sooner rather than later.

And yet the man who hijacked Downing Street in 2019 could upstage Bear Grylls with his capacity to survive in gruelling conditions. He may have just enough electoral reserves to see him through the winter to spring.

Whatever happens, for Scotland, it matters a lot. Boris Johnson has little feel for Scotland but his political fate will have a significant bearing on this nation’s future.

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