Nicola Sturgeon resigned to avoid being the leader who presides over the end of Scottish independence 'dream' – John McLellan

Shortly after Alex Salmond’s resignation, he published his diary from the referendum campaign, ‘The Dream Shall Never Die’. His successor has now made sure she won’t be the one to kill it off for good.

The great thing about quitting while you’re ahead, which as far as voting intentions go Nicola Sturgeon unquestionably still is, is you don’t have to take responsibility for an unfolding disaster of your own making. In a resignation speech characterised by self-worth and delusion, she almost admitted as much.

Her explanation that going now would leave the SNP free (her word) to choose how to approach the last great push towards independence sounded astoundingly arrogant even for her. The SNP will do what I say, even if I’m wrong, because I’m the unchallengeable leader, was her clear message, and she wanted everyone to believe her decision was to ensure the party made the right decision, no matter what she thought.

There are two problems with this, the most obvious being the party was already prepared to make that decision, and the special SNP conference next month to discuss the independence roadmap was arranged precisely because of the growing realisation that her “de facto referendum” plan for the next General Election was virtually guaranteed to kill off any last hope of separation for decades.

Apart from the supreme arrogance of telling voters what they were voting about, the need to achieve over 50 per cent of the vote, which the SNP just failed to do in the 2015 landslide when Labour and the Lib Dems were on their knees, was and is regarded as virtually impossible. The likelihood of the SNP ditching her plan was growing by the day, but that would have been a humiliation from which she might not have recovered.

The alternative, to switch the ploy to the next Holyrood election, is equally implausible and because she was unlikely to face a palace coup the confusion and division about the future of the independence movement would have been hers to own. The problem with her self-declared omnipotence is everything tracks back to her: the assault on the whisky industry, the looming disaster of the deposit-return scheme, and the remarkable achievement of getting even SNP voters to support the UK Government block on the Gender Recognition Reform Bill.

As well as alienating the oil and gas sector, her enthusiastic partnership with the Greens has not created a momentum for independence, but set her government on a road to conflict in which the deposit return scheme is just the first of a host of Green-driven policies which will hit ordinary people the hardest.

That all this was happening as the independence bandwagon was coming off the rails and her approval ratings were slipping into negatives, all point to now very much being the right time for her to go while her reputation as a winner remains intact. As she said in her speech, she has given her entire adult life to the cause of independence, so no wonder she did not want to be the SNP leader whose over-reaching self-belief was responsible for killing off her ultimate goal.

That fate will fall to the next leader, whoever he or she may be, because Labour’s unelectability and Brexit dealt her a hand no successor will enjoy.