The Tories’ Douglas Lumsden might have secured the most votes in Aberdeen South but the winner of the by-election was Stephen Flynn.

The Cabinet Secretary for Economy, Tourism and Transport greeted the news of his party’s defeat, in a by-election caused by his transfer to Holyrood, with the ominous comment: ‘A tough night in Aberdeen that some will need to reflect on, quite heavily.’

No prizes for guessing who that particular barb was intended for. Keir Starmer isn’t the only leader having to watch his back.

Flynn is every bit as ambitious as Andy Burnham and it is the worst-kept secret in Scottish politics that he wants John Swinney’s job.

Yet the man he wants to see do some heavy reflecting seems minded to carry on as before. Swinney’s strength is his determination. It’s his weakness, too.

The SNP lost Aberdeen South because of Net Zero.

True, the Peter Murrell revelations probably didn’t help, but Swinney dealt with the scandal the way the SNP always does: suffer a few days of bad headlines, block any attempt at scrutiny, then move on.

An already-fading row about party funds did not produce the swing that carried Lumsden to victory on Thursday. That was the result of the SNP’s abandonment of oil and gas workers.

The Net Zero agenda has been devastating for the Granite City. The fossil fuels industry was already in decline but the SNP government under Nicola Sturgeon took a conscious, ideological decision to hasten it by opposing further oil and gas exploration.

That was the price of cosying up to the Greens but it also reflected an internal shift, away from ‘It’s Scotland’s oil’ to a new SNP emphasis on social progressivism and identity politics.

For Aberdeen, it was the worst decision at the worst time.

When the city needed the Scottish Government on its side, pushing the equally Net Zero-fixated Westminster political class to keep the North Sea open for business, it instead got layoffs, shutdowns, a contracting labour market, and plummeting house prices.

A city and its surrounding suburbs were sacrificed on the altar of political fashion and expedience.

Lumsden’s emphatic victory means the party must work hard to bring Aberdeen South back on-side before the next election. Not only this constituency but the North East as a whole seems to be firming up into a second blue wall, after the Tory redoubts in the Borders.

Their entrenchment there saved the Conservatives from a much more comprehensive defeat in May’s devolved elections, and the Nationalists will have to strategise alternative paths to electoral victory that don’t include Aberdeenshire.

Defeat in Aberdeen leaves Swinney weakened and the awareness that Flynn is looking over his shoulder, waiting for him to foul up again, makes it all the more probable that he will foul up. Swinney cannot afford many more major errors.

Not that Flynn’s schemes are guaranteed a smooth path. His dig about the need for reflection drew a pointed response from Kate Higgins, former special adviser to Swinney and a staunch ally of Nicola Sturgeon.

‘I do hope that “some” includes you,’ she told Flynn, ‘the by-election was, after all, caused by your choices’.

A matter of hours after the loss in Aberdeen South and already the SNP was fighting with itself in public. Make mine a large popcorn, please.

Flynn's is a personality you either take or leave, and some within the party would much rather leave it.

They see him as too blokey, too cocky, and wonder if he wouldn’t drive away more supporters than he brings in. 

Then there are the practical considerations. Ambition will only get you so far and governing calls upon a different set of skills from rabble-rousing in the Commons and plotting in WhatsApp groups.

The Scottish Government labours under any number of intractable policy problems and inheriting them would require Flynn to have a credible plan to tackle each one.

A leadership challenge might not be a coronation, either. Those who see Flynn as self-serving and fear he would trash the Sturgeon- Swinney legacy would want to see a competitive contest.

There would also be disquiet about three male leaders on the trot. An obvious Stop Flynn candidate would be Deputy First Minister Jenny Gilruth, a Sturgeonite more likely to double down on the progressive approach of recent years rather than shift in a populist direction.

What all this means for Scotland is that the ruling party at Holyrood is set for further division, plots, personal ambitions and possibly a leadership poll.

A government this distracted will find it difficult to lead the country well. Good news for the political class, less so a Scotland in dire need of sound leadership.