The SNP must now do the soul-searching it has been putting off since 2014

Nicola Sturgeon is due to answer her last First Minister’s Questions at Holyrood this week, bringing down the curtain on an era of SNP rule that, combined with the tenure of her predecessor Alex Salmond, extends to 16 years.

Defeat for the Yes campaign in the 2014 independence referendum ought to have led to a period of introspection for the SNP and the wider Nationalist movement.

But instead of examining why they lost, the party leadership doubled down. Scots, it seemed, had voted No because of some peculiar contrariety. MI5 may well have been involved. The focus immediately fell on putting the question to the people again as soon as possible.

A few days after the 2014 vote, Mr Salmond and his then deputy Ms Sturgeon declined to attend a service of reconciliation at St Giles Cathedral in Edinburgh aimed at healing the divisions opened up during the campaign, thereby setting the tone for the next eight and a half years of SNP rule.

Nicola Sturgeon, pictured holding a campaign rally in 2017, will step down as First Minister and SNP leader later this month. Photo by Jeff J Mitchell/Getty Images

As she took the reins of the Nationalist movement, Ms Sturgeon continued in Mr Salmond’s belligerent style. Perhaps it was easy to assume support for independence would only ever rise, and that aged intransigent No voters would soon simply die off - ignoring the fact that today’s young people are tomorrow’s old people, and that voters’ priorities and values change as they get older.

Instead of strengthening the case for independence, it was allowed to stagnate, despite circumstances at Westminster that could scarcely have been more favourable.

There was only so long a lid could be kept on the divisions within the SNP, an assembly of fellow travellers united by a common destination but set on very different paths. The longer the internal pressure was allowed to build up, the more spectacular the explosion we are now seeing.

The SNP needs to have the conversation with itself it should have had after the 2014 referendum defeat. If ever there was a party crying out for a period in opposition to sort itself out it is this one. Inconveniently, however, it has up to three years left in government until the next Holyrood election.