John Swinney has only two years to rise to the biggest challenge facing the SNP: how to de-couple it from the ruinous reign of Nicola Sturgeon. It was Humza Yousaf’s failure to do this that led directly to his political downfall barely a year after he had become First Minister of Scotland.

Anyone harbouring doubts as to how harmful the Sturgeon era was for the SNP need only look at all the recent projections for the impending Westminster election. The party is expected to lose up to 28 seats and, of course, much can change in the intervening months. But when some MPs who were confident about holding their seats a few months ago are now telling you they’re not so sure it’s a sign that this party is standing on the precipice of political oblivion.

This is reinforced by the number of SNP diehards telling me that they feel the party needs to experience a spell in opposition at Holyrood to recover fully from the damage wrought by Ms Sturgeon and her acolytes.

Nor can you over-estimate how much the Scottish Greens in government have damaged the SNP’s reputation. The Bute House Agreement lasted almost three years, yet not once during this time did I ever hear an SNP supporter or Scottish nationalist ever say: “The Scottish Greens have been good for us.”

At Holyrood last week, on the day that it became clear that Mr Swinney was virtually assured of becoming First Minister, I expressed my bemusement to several MSPs that Mr Yousaf hadn’t stood his ground and faced down the Sturgeon loyalists who have hollowed out this party. This was greeted with uncomfortable shrugs, but no denials.

He was, after all, the leader of a party that had won more than 10 elections in four different jurisdictions since 2007. He had become leader following a bruising six-week contest barely 14 months ago. He had decided to ditch the two Scottish Green ministers and to terminate their Harry Potter departments because it was becoming clear that they had become an electoral liability and a blight on the wider independence movement.

Then it emerged that a subversive Star Chamber of Sturgeonistas had threatened to fillet him in last week’s no-confidence votes if he cut a deal with Alba’s Ash Regan. It was probably the first time in his gilded life and professional career when he’d ever encountered a hint of jeopardy.

He should have faced down this cabal and simply declared his intention to go to the electorate. Then he should have said something along the lines of “you’d better hope I don’t win. Because if I do, then I’ll see to it that your careers in politics are over (insert your own profanities in the appropriate places)”.

The conduct and clandestine manoeuvring of this faction also confirmed something else many of us had long suspected: that this had never been about Scottish independence for them. Rather, to them the SNP exists merely as a conduit to impose a cultural revolution where science, reason and equality have been replaced by the magic beans of the gender cult. And all of it rooted in the intimidation of feminists and gay people.

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The extent to which he can bring back those many activists who have deserted the party specifically because of this will define his tenure.

Reports over the weekend suggest that the Sturgeon faction and the Scottish Greens are now gathering to resist any attempts by Mr Swinney to distance the party from self-ID. The Scottish Greens continue to delude themselves that they have any relevance in the lives of most people living in Scotland.

They’re urging Mr Swinney not to dilute the proposed ban on conversion therapy, even though such a practice is inherently homophobic and seeks to remove vulnerable children from the protection of their parents.

Mr Yousaf’s unwillingness to face down these malevolent forces emboldened them to bring him down. Mr Swinney simply cannot allow the Greens or the Sturgeon loyalists to dictate the future direction of his administration.

He could begin the task of marginalising them by appointing Kate Forbes to be his deputy and handing her the Finance brief. No one else in the party is better qualified to handle this area. And no one else is more capable than her of winning over the soft unionist votes required to get independence over the line when the opportunity next presents itself.

The Herald: How will John Swinney deal with the transgender issue?How will John Swinney deal with the transgender issue? (Image: free)Ms Forbes too must be prepared to play for keeps. Her Christian faith shouldn’t prevent her from deploying dark political arts and stratagems to rout her opponents within the party. She is possessed of a far greater and more nimble intellect than they and enjoys the support of the party membership. She shouldn’t be above using all of these to expose them and cast them aside.

Mr Swinney must also do as Anas Sarwar has now finally done and declare the scientific truth that transwomen are men and that the full findings of the Cass Review will be implemented with immediate effect. This aligns with the instincts and preferences of the overwhelming majority of Scottish voters.

If he retreats from these challenges - as his predecessor did - then his tenure will last barely much longer than his did.

In his acceptance speech yesterday after being formally installed as SNP leader he said his focus will be “the economy, jobs; the cost of living. It will be the NHS, our schools and our public services.” However, he’ll simply not be taken seriously in any of these pursuits if he can’t bring himself to state straightforward scientific truths.

He also said that while the SNP has a mandate to form the government “it does not mean we can stop listening to people and voices outside our party.

The polarisation of politics does not serve our country well.” Later, he said: “We need to stop shouting at each other and talk. More than that, actually, we need to listen.”

Nicola Sturgeon’s refusal to listen to wise counsel inside her own party about the consequences of gender fanaticism and the bullying of females was exposed during the Isla Bryson and Andrew Miller scandals last year.

It’s vital that Mr Swinney sends a clear message to the Scottish public that never again will any Scottish Government allow itself to be manipulated by the Scottish Greens, the most unsuccessful party in the history of the Parliament and the SNP’s most expensive mistake.

If he allows them anywhere near the levers of power then his tenure will end at the 2026 Scottish election.