The Peter Murrell scandal started with one man’s criminal avarice – but now devolution is in the dock.

Pressure is mounting on both sides of the Border for inquiries into the affair which has turned Scotland into a laughing stock.

John Swinney and his colleagues are determined to avoid anything approaching a forensic Murrellgate probe at Holyrood.

That means attention has turned to the Scottish Affairs Committee (SAC) in the Commons to take it on, possibly holding hearings in Scotland.

The thinking among some Labour MPs is that the change of venue would shame the Nationalists into cooperating with its work.

SAC members are due to consider the matter on Tuesday and Conservative MP Andrew Bowie, the Shadow Secretary of State for Scotland, is calling for Dave Doogan, the sole Nationalist MP on the committee (and the SNP’s Commons leader), to ‘do the right thing and back a probe’.

Tuesday will see a vote at the Scottish parliament on an inquiry – but the odds are that the Greens will bail out their former partners in government and vote it down.

But there are bigger issues at stake and one of them is the credibility of Holyrood, or more accurately whether it has any left.

If MSPs can’t bring themselves to put country before party allegiances, then what precisely is the point of this white elephant of a parliament?

It was never meant to be a giant broom sweeping scandals under the carpet, or facilitating the kind of tribalism which could mean we never get to the truth of Murrellgate, and how it was allowed to happen.

For that reason, the Holyrood vote is an important test of our national legislature, but the smart money says the spineless Greens will cave in to SNP pressure – and put the kibosh on any prospect of an inquiry.

The Greens says an inquiry would turn the parliament into a ‘political circus’ – though it already resembles one, in large part thanks to the Greens.

The spotlight then shifts to the Commons and in particular Mr Doogan.

He will vote against a probe as he says an inquiry would be an ‘unprecedented abuse’ of the system and a ‘party political stunt’. But the committee could decide to back an inquiry even if there’s no unanimity.

Of course, refusing to support one to try to prevent more negative headlines for the SNP – a futile endeavour – would also be something of a political stunt.

Nationalist MP Pete Wishart, a former SAC chairman, has warned ‘embarking upon an inquiry into matters that properly belong to the jurisdiction of the Scottish parliament, and doing so without its consent, risks reopening old divisions and damaging relationships’.

Well, Mr Wishart would know all about divisions – as an SNP ultra-loyalist, he has helped to stir up enough of them in his time.

The SNP might try to withhold cooperation from SAC hearings, whether in Edinburgh or London, but if a witness refuses to provide evidence to a Westminster inquiry, a committee can issue a summons.

Defying a summons can lead to a witness being found in contempt of Parliament – with sanctions including admonishments, fines or imprisonment.

As for the WhatsApp messages which must have been sent back and forth on SNP finances between party bigwigs, the chances of their retention must be somewhere between low and non-existent.

You’ll remember that a potential treasure trove of such communications sent during the Covid era was cast into the ether by Mr Swinney and his cohorts – including his then boss Nicola Sturgeon.

One former SNP member last week said the party was operating like a ‘criminal syndicate’ after Mr Swinney admitted a £667,000 fund ‘ring-fenced’ for an independence referendum was used for election spending.

The SNP has been trying to con Scots for years into buying its vision of an independent country where everything is free and the evil Tories are vanquished forever.

It shouldn’t be any great surprise that it made fools of its own supporters – many of whom are rightly up in arms over the brazen deception.

That brings us neatly back to the ultimate conman, Peter Murrell, the shamed former SNP chief executive and Ms Sturgeon’s estranged husband, who admitted last month to embezzling more than £400,000 of party funds.

He used it to buy an array of goodies from the pedestrian to the outlandish, and Ms Sturgeon benefited – unwittingly, she insists – in the form of presents bought with stolen cash.

It’s an almighty mess, and the taxman is now being called upon to investigate whether VAT was illegally claimed on the embezzled goods.

Murrell used false accounting trails to cover up his extensive fraud over a period of 12 years, though some of these wheezes lacked imagination and were hardly the work of a criminal mastermind.

He used some of the stolen cash to buy Sherlock Holmes novels – but Murrell was no Moriarty. That said, he kept it up for long enough, and it took detectives years to figure it out, costing taxpayers more than £2million – and we’re footing the bill for his lawyers, too, after he qualified for legal aid.

It’s worth reminding ourselves of the extent of the criminality, and the related issue of SNP misspending of ‘ring-fenced’ donated cash – though Police Scotland says it won’t re-investigate this, despite Mr Swinney’s bombshell admission last week.

We’re expected to believe that Mr Swinney, an SNP big cheese for decades, knew nothing of what was unfolding – while Ms Sturgeon has become a figure of ridicule over her claim that she was in the dark about her husband’s crime spree.

She saw nothing odd about the £81,000 Jaguar outside their home or a 24ft motorhome, costing £124,000, parked at her mother-in-law’s house in Fife.

Ms Sturgeon has ‘no conscious memory’ of the latter, but perhaps an inquiry could help her to remember.

Mind you, she has a long track record of giving her interrogators the runaround, as we saw during her evidence to Holyrood’s Salmondgate inquiry.

If you think none of this merits closer examination, then the chances are you’re in the SNP high command.

Just about everyone else, apart from Mr Swinney’s Green lapdogs, wants evidence on oath from the key protagonists of the Murrell saga.

Mr Swinney is a zombie First Minister – despite his re-election only a month ago – leading a government steeped in sleaze.

He’s drinking in the last chance saloon unless he backs a probe – and he should order his MSPs to do so.

This week, we’ll find out whether our democracy is up to the job of holding the SNP to account – or whether the Nationalists will be allowed to drag it further into the mire.