AND still, remarkably, the CalMac ferries debate drags on, each week bringing forth an unappetising new detail.

Earlier this week a “missing” critical email suddenly materialised, moments before a key debate. In the Holyrood chamber, Willie Rennie spoke for many when he said the disclosure that very morning was difficult to believe, given the government’s track record on openness.

Audit Scotland, which has investigated the ferry contract, noted the discovery of the email but said that its own concerns had not yet been addressed. In a damning phrase it said there remains “insufficient documentary evidence” to explain why ministers opted to proceed with the Fergusons contract, given the “significant” risks and concerns raised by Caledonian Maritime Assets Ltd.

In a BBC interview the SNP's Cabinet Office spokesperson, Stewart Hosie MP, downplaying the matter for all he was worth, denied that public money had been wasted on the Calmac affair. The two ferries were, he said, “a little late” – an entertainingly novel way of describing something that is four years behind schedule.

More: Jim McColl has dismissed as “a lie” the First Ministerial assertion that the Ferguson Marine shipyard would have closed without the contract for the two ferries. Ms Sturgeon’s response was characteristically robust – she has repeatedly said she was motivated by the desire to protect crucial jobs – but, even allowing for the animus that exists between the two, the accusation of lying is a serious one.

It has also been reported that Scottish taxpayers face a substantial bill for the upgrading of the nationalised shipyard if it is to make competitive bids for essential new contracts.

We’ve seen attempts to blame the disgraced former minister, Derek Mackay, for giving the contract the green light; several ministers had oversight of decisions and budget but the Government has been intent on pinning the key decision on him. We’ve seen the SNP’s deputy leader fleeing into the Holyrood canteen to avoid reporters’ questions. The Deputy First Minister, John Swinney, denies giving the “final nod” to the contract, but admits to giving it “budget approval”.

Owing to a blunder, part of a Government internal email chain was improperly redacted, allowing blacked-out text to be revealed through a simple cut-and-paste move. Episodes such as these are the material more of the political satire, The Thick of It, than of an avowedly modern, forward-looking administration.

For how much longer will this sorry chapter be allowed to fester? Set aside the concern that it must be distracting ministers and focus on the fact that the affair speaks to a distinct lack of transparency and honesty.

Remember the words of Stephen Boyle, Auditor General for Scotland, just a few weeks ago: the failure to deliver the two ferries, on time and on budget, he said, exposed a multitude of failings. “A lack of transparent decision-making, a lack of project oversight, and no clear understanding of what significant sums of public money have achieved. And crucially, communities still don’t have the lifeline ferries they were promised years ago”.

Much has been made of the SNP government’s secretive, centralising instincts. The investigation into Alex Salmond yielded some evidence of what might charitably be described as a lack of openness. The precise circumstances surrounding the departure of Eilidh Mactaggart, CEO of the publicly-owned Scottish National Investment Bank (SNIB), have yet to be disclosed; she received an exit payment of £117,500 instead of working her notice period, prompting questions to be asked in the chamber.

And so it goes on. It may be that the Scottish Government has been in power for so long that whatever commitments it once harboured towards transparency are now an inconvenience, a thing of the past. Governments of all colours, sadly, end up protecting secrets while preaching openness.

The SNP government’s sole raison d’etre is to bring about independence, so its reputation for competence has to be maintained at all costs. And because a stain on the government is also seen as endangering the indy dream, as our Scottish political editor, Tom Gordon, points out, the temptation to suppress information for the sake of the cause is all but irresistible. But the SNP’s secrecy, he correctly adds, is ultimately self-defeating, and erodes trust.

Ministers have treated the chamber, and notions of accountability and transparency, with attitudes that range from the cavalier to the contemptuous. You don’t need to be politically opposed to the SNP to believe that something is badly amiss – or to demand, in the case of the ferries, a full, public, judge-led inquiry.

Ministers will doubtless raise an aghast, collective eyebrow at such a suggestion. There have already been, they will say, inquiries into the matter. We have published documents on the government website (though many have been redacted). Furthermore, why risk washing dirty laundry in public and give fresh ammunition to the rival parties?

But trust has without question been eroded, and will continue to shrink with each new disclosure, each new combative assertion by McColl, each freshly-uncovered email chain, each uneasy attempt to shift the blame. We do not yet know the unexpurgated story of the ferry contract. We need to know to what extent lessons will be learned, in Mr Boyle’s words, to avoid a repeat of problems of future new-vessel projects and other public-sector infrastructure works.

A public inquiry would of course be expensive and time-consuming. The Edinburgh Trams inquiry is still to report back its finding despite being announced in 2014. The process of setting up a ferries inquiry, of witnesses being questioned and documents scrutinised, of evidence being mulled over and a lengthy report finally being assembled, will take a long time. It might end up putting ministers in a bad light; but then again, it might not.

In view, however, of the vast sums of public money already squandered, in view of the many grey areas and the unedifying multiplicity of contradictions, accusations and heated denials, a public inquiry might be the best way forward, as well as restoring some of the trust that has been needlessly lost.

Festival turns over a new leaf

THE Edinburgh International Book Festival, long one of Scotland’s cultural highlights, has brought countless bestselling authors to Charlotte Square. It continues to evolve; this year and next it will be staged at Edinburgh College of Art before moving, in 2024, to the Edinburgh Futures Institute in Lauriston Place. This will allow the festival to expand and innovate further, and to open a new chapter in its spendid history.