To adapt a line from the Scottish play, nothing in office became Humza Yousaf like the leaving it. His declared departure was dignified and emotive. One can only express personal empathy. Reaching this conclusion must have been exceptionally difficult after only a year as First Minister.

Eventually, though, he was brought down by arithmetic and animosity. By arithmetic in the Scottish Parliament where he had shed the support of the Greens and did not relish the prospect of relying upon Ash Regan, the former SNP leadership contender who defected to Alex Salmond’s Alba party.

By animosity – aimed at him from the exasperated and infuriated Greens. On Thursday morning, he peremptorily ended the Bute House agreement and, in so doing, expelled the two Green Ministers from government. Understandably, they were somewhat upset.

Yes, they had already begun their own review of the pact, unhappy with the Scottish Government’s decision to abandon interim climate change targets. But there might have been a reconciliation – or perhaps an agreed loosening of the deal.

Instead, Humza Yousaf shattered the pact himself. Mr Yousaf knows – he knows – that this was a blunder. It infuriated the Greens when a more emollient approach might have worked. He lost their trust. They regarded his actions as betrayal.


Humza Yousaf throws the baton down and runs for the hills

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I understand his motivation. He wanted to get on the front foot, with his own agenda and his own focus on issues like economic growth. Instead, he ended up shooting himself in that same foot. Perhaps he was thinking a bit too much about the impending UK General Election.

SNP MPs need the party to take a clear, distinctive line – in the middle ground, addressing the cost of living, remote from controversial issues such as gender. Did Mr Yousaf heed that concern too much – perhaps forgetting the fundamental need to sustain a working majority in the Scottish Parliament?

Mr Yousaf still had an option. He could have survived – just – with support from Ash Regan in the confidence motions tabled by the Tories and Labour. But at what price? One senior insider told me that anything faintly resembling a deal with Alex Salmond would have been anathema to SNP members. Another said that might have got Mr Yousaf through this week. But what about next week? Arithmetic and animosity would still count against him.

So what now. Mr Yousaf remains First Minister until a successor can be appointed. The SNP’s National Executive will meet to agree a timetable for a new leadership contest. As long as he stays in office, there is no vacancy. And so no requirement to trigger the search for a new First Minister within the 28-day period laid down by Holyrood’s rules. That starts when he tenders his resignation to the King.

The Herald: Humza YousafHumza Yousaf (Image: free)

But what about those confidence motions? Both are still extant. The Tory motion targets Mr Yousaf personally. In effect, it is overtaken. If tabled and endorsed, Mr Yousaf would simply say that he is on the way out anyway. The Labour motion is different. It targets the entire SNP Government.

However, the SNP calculation is that it will fail, not least because there is limited enthusiasm for another Holyrood election, to supplement the UK contest. Which leaves Mr Yousaf in office but remote from power. As to his successor, names mentioned include Jenny Gilruth, Mairi McAllan and Neil Gray. Others argue for John Swinney, in search of stability. If he wants it, it is his.

Then there is Kate Forbes, narrowly defeated by Mr Yousaf last year. The Greens say they could not work with her, given her socially conservative views on such issues as same-sex marriage.

That may irritate some in the SNP – who will revive talk of the tail wagging the dog. I hear that concern. But the SNP needs to regroup, needs to consider that pending UK election – and, of course, their standing desire to pursue independence. All undermined by internal turmoil. Tough on Kate Forbes, perhaps, who is not lacking in ability. But those two Holyrood factors may count against her. Arithmetic and antagonism.