How self-righteous SNP's attempts to claim the moral high ground backfired – Alistair Carmichael

Apparently Mr Murrell bought his wife (the then First Minister Nicola Sturgeon) a nine-carat gold pendant during a by-election jaunt that summer. The news raised several important questions, not least of which is: if you are spending someone else’s money, surely you might have sprung for 18-carat gold?

Wry jokes aside, the former SNP chief executive’s fall from grace and his embezzlement guilty plea should be a serious lesson for all politicians and all political parties: you hold yourself higher than others at your own peril.

READ MORE: Why John Swinney can't dismiss the case for Holyrood inquiry into Peter Murrell case

‘Good chaps’ theory of party governance

For many years in the wake of the 2014 referendum, the SNP rode a wave of political energy. A new, purer, more righteous movement was on the march, while under the surface, all manner of poor behaviour was hidden. For many in Scotland (and beyond), it seemed perfectly credible to see the SNP under Nicola Sturgeon as offering a clean and uncorrupted form of progressive politics.

Even with the SNP government re-elected for a fifth term earlier this month, I suspect there are few left who would claim that the 2014-15 fervour is still driving them. Like it or not, the SNP are now well and truly part of the ‘establishment’, with all the baggage that entails – including the growing realisation that while the SNP may not be inherently ‘worse’ than other parties, they no longer sit on the moral high ground they once claimed.

Painful though it may be for some, that is a healthy thing to recognise. A party that has run the Scottish Government for two decades simply cannot be one run solely on good faith and a ‘good chaps’ theory of internal governance. If that wasn’t self-evident before Police Scotland’s Branchform investigation, it must surely be clear now.

READ MORE: Westminster should hold Peter Murrell SNP embezzlement inquiry if Holyrood doesn't, say MPs

A full and frank investigation

The question, then, is how the SNP responds – whether they grasp the opportunity to tackle the root problems that led to Branchform and myriad other headaches, or revert to their comfort zone of battening down the hatches and fighting against transparency.

Quite apart from the interest of our national politics (in a time when populism is rising and election turnout rates are hitting dangerous lows), it is in the SNP’s own interest to have a full and frank investigation into the blind eyes and poor accountability structures that led to where they are today. To put Branchform down to ‘one bad apple’ is to miss the wider system that allowed Murrell to do what he did, without challenge, for so long.

That should be a lesson for us all. Tempting though it is to slip into triumphalism, no party has a monopoly on hubris or poor judgment, on right or wrong, on the high ground or the low. The saying goes that all politics is local. An equally important rule – for the SNP and for all who sit on the moral high ground for too long – is that what goes up, must come down.

Alistair Carmichael is the Scottish Liberal Democrat MP for Orkney and Shetland