Are we witnessing the death throes of Scottish nationalism as we have come to know it? That may seem an outrageous and fantastical question, but it is worth the asking. Just as Brexit represents the most historical political decision of the UK’s contemporary history, so the rejection of independence in 2014 represented the most crucial decision for modern Scottish political history and we are still seeing how it is playing out.

While the Liberal Party defined what was called Home Rule, Scottish nationalism has historically been defined by the SNP. There was a time that I can remember that people of my parents’ and grandparents’ generations dismissed nationalists as nothing other than cranks. After the Hamilton by-election and the two general elections of the mid-seventies that all changed.

No one now should underestimate the strength of support for the SNP, it remains the largest Scottish political party in both Westminster and Holyrood, and despite recent setbacks in the last three national and local elections the SNP remains far ahead of the Scottish Conservatives. And while support for independence has been declining, it has not suffered a collapse. Indeed, it benefited from the heightened period of political debate the referendum provided and took on tens of thousands of new members, including activists that previously supported the more radical sections of the Scottish Labour Party.

First Minister Nicola Sturgeon receives the Sustainable Growth Commission report from commission chair Andrew Wilson

In such a positive factually based context why would anyone choose to believe Scottish nationalism is about to change and even go into reverse?

I believe Scottish nationalism is and always has been a movement rather than a party. The possibility of delivering Scottish independence, to get it to a vote of 50 per cent plus one, has always rested on developing a consensus across the differing political philosophies. While the SNP has sought to steer a centre-ground course it has managed to bring people into nationalism’s fold, either as party supporters or those of other political hues that felt the SNP provided the required leadership and best campaigning logistics. It has also, deftly, convinced those of the radical left and even some on the classical liberal right that independence could be achieved and was the best vehicle to realise their wildest dreams of a socialist nirvana or become Europe’s very own Hong Kong. Both of those groups have been utterly duped and it is the realisation they may not achieve their dreams that threatens the SNP’s leadership of nationalism.

The recent report by the Growth Commission established by Nicola Sturgeon is the catalyst precipitating the SNP’s calamity.

It is not so much that the report is economically unconvincing – although its flawed assumptions are just as much a threat to Scotland’s future prosperity as those in the discredited White Paper “Scotland’s Future” – it is that it represents a wake-up call to those on the left that thought Scottish nationalism, as shaped by the SNP, was their best hope for salvation.

Opposition amongst Scottish nationalists to the report’s recommendations is now stirring and becoming vocal both inside and outside the SNP, undermining the SNP’s hegemony of leading the nationalist legions.

Common Weal director Robin McAlpine, a man who in travelling to meetings to make a radical left case for independence wears out his weight in shoe leather, said: “Please, I beg of you, understand what is actually in this report before you start calling it credible, well- researched or a step forward. I don’t believe it to be any of these. And what kind of independence is this anyway – rule by London markets via Charlotte Square finance sector viceroys?”

Or what about economist and former SNP MP George Kerevan, who in reviewing the Growth Commission report sounded a warning: “There are those who will not be enraptured by this document – the poor, the unskilled, and the working-class voters who want hope in their lives and might be persuaded that an independent Scotland will give it to them. These are the very voters Jeremy Corbyn is also appealing to.”

Or this, from Scotsman columnist Darren McGarvey: “If the big idea is simply to rebrand the fundamentals of the UK economy, so that independence becomes more attractive to those whose entrenched advantages are threatened by a radical alternative, well, that’s a very different proposition, isn’t it?”

These are not just straws in the wind. They represent a realisation amongst those who help shape nationalist thinking that Nicola Sturgeon’s strategy for obtaining independence may lock them into a form of central planning that delivers crony capitalism in a kilt.

These voices are not challenging independence itself but they are raising the question, much more vocally than we have heard or read before, that the current SNP leadership’s route to deliver it – and what it might actually deliver – must be doubted and debated. Before the Growth Commission’s report we occasionally heard the odd grumble, most usually from discontented Greens, about the SNP’s domination of the Yes campaign, but we now have a new landscape, one where an independent Scotland might not be what those on the radical left wished for. More troubling still, it may be worse than the status quo; it may end up creating a centrally-run Scottish state with all the vices of social injustice many campaign against but with a self-inflicted austerity that will see Scotland’s greatest growth industry be its food banks.

As I have argued in this column before, if one looks to Iceland, Norway, Denmark, and other smaller countries the SNP mentions in its justification for independence, they regularly have governments formed or led by conservative parties.

The shine is now coming off Nicola Sturgeon’s leadership of the SNP. She has made many ill-judged comments about the need for a second referendum that have rebounded on her and her party, causing the public to choose to vote for her opponents; she has conducted herself crassly with petty stunts, such as disrespecting Theresa May when she visited Bute House by displaying two saltires behind her rather than the flags of both governments as is protocol; and she has presided over a collapse of public service delivery and the defenestration of local authorities that her government is completely responsible for. All of this hurts the case for nationalism.

I do not expect the coming SNP conference will be anything other than a rally for Sturgeon, but I sense the tide is turning and the SNP’s domination of independence will never be the same.

l Brian Monteith is editor of ThinkScotland.org

Brian Monteith: Nationalism is no longer Nicola Sturgeon's poodle