If you want to know what’s going on with public opinion, there’s all the usual sources: the polls, the surveys, the vox-pops, the in-depth psephological analysis by top political scientists. And my kitchen table.

The precise statistical significance of my kitchen table remains uncertain, but the way the chit-chat round it has changed is interesting. Most of the foundations of Scottish public life are remarkably resilient – 45% belief in independence, support for the SNP in its strongholds – but the chitter-chatter in kitchens like mine tells a slightly different story.

The story is shift essentially, or an element of it, and the friends I had staying this weekend were fairly typical. We sat at the table and played monopoly and backgammon and when they weren’t winning by being dirty cheats, the chat was about life and news and politics and the upcoming election. And what it revealed, as it has on other occasions, is a change in attitude, a shift of view, that’s troubling for the SNP but revealing too about the party’s increasingly confused relationship with the middle classes.

If you doubt this and question the evidential basis of my kitchen table, I’m pleased to say that this weekend there was other, possibly more robust, data from the Diffley Partnership. What they did was they analysed the 27 polls conducted in Scotland in the year since the resignation of Nicola Sturgeon and it showed that the switchers from the SNP, like my friends at the table, have largely come from the middle classes.

Deeper down, the data shows something else as well, which is that the attitudes of middle-class voters appear to have changed most significantly in the spring and summer of last year, which chimes with what my chums were saying. Nicola Sturgeon was a key part of support for the SNP, which strengthened during the pandemic. Then came her resignation, the motorhome, the tent in the garden, dot, dot, dot. In February 2021, net trust in Sturgeon was +18; it is now -19.

You could try and downplay the importance of the Sturgeon factor; Tony Benn used to say issues matter more than personalities, but that’s not how it works really. Sturgeon was important; people liked her, and she was apparently competent and trustworthy. But it started to shift when the scandals broke. I saw some of the shenanigans for myself when I was up at her house at the height of the furore and it was a bad, bad look. It changed attitudes. It started the movement.

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However, the harder thing for the SNP, who need to keep the middle-class voters they started to win over about 10 years ago, is that Sturgeon isn’t the only factor that’s changing minds round kitchen tables. Also problematic is a policy programme that’s sending mixed signals to voters who are a bit better-off. Does the SNP want to protect their income, or take a bigger slice of it?

For a while (late-Salmond and early-Sturgeon) it looked like the SNP wanted to be seen to be on the side of the middle class. It told them their children could go to university without paying tuition fees, and they could go to the chemist to get their prescription and not have to pay anything, and their council tax wouldn’t go up, and they would get a payment towards their fuel during the winter, and so on. They were policies aimed at middle-class voters and it worked.

In more recent times however, the message has been more untuned and unfocused. I’m writing this 50 years to the day since Denis Healey made his famous “til the pips squeak” remark about certain well-off taxpayers and under the Labour government of the time, the highest rate of income tax was 83%. We’re nowhere near those days of course, and even if we were, only a small number of very well-off people would be affected. But in some ways the situation in Scotland is worse than that, as in worse for the SNP.

The issue is that, as far as Scottish voters are concerned, the higher tax starts for people earning £28,000 a year because that’s the threshold for Scottish taxpayers to pay more than their UK counterparts. Humza Yousaf is also making it worse by introducing a new tax band and raising the top rate. It means many middle-class voters will certainly pay more tax and have less disposable income. But the worst bit from an SNP strategical point of view is that it bites down hard and it bites down low, on people earning no more than the average income. The chat round the kitchen tables is we’re feeling it.

To make things worse, Mr Yousaf has been sending out other signals worrying for voters with an eye on their incomes. Last summer for example, the First Minister said he wasn’t all that sure any more about universal school meals. “I’ve got a 14-year-old now,” he said. “Should people be paying for her free school meals when I earn a First Minister’s salary? I don’t think that’s the right way to use that money. The better way is to target it to those that need it most.”

In some ways, that’s fair enough – I’d be supportive of a much more targeted approach to benefits and pay-outs, including the ones I receive – and it may not come to anything anyway. But casting doubt on the principle of universal benefits while also raising taxes on average incomes is a classic mixed signal and it’s unsettling, and potentially costly, for middle-class voters.

Another example is the current debacle over council tax. Whether they admitted it or not, the SNP’s original freeze on the tax had the biggest positive effect on the middle class; councils then started raising council tax again only for Mr Yousaf to announce last year that it would be frozen once more. In fact, it’s still not entirely clear if that’s what’s actually going to happen; a couple of councils have buckled and agreed, but others appear to be resisting.

The question is then: what is Mr Yousaf trying to tell us, the people gathered round our kitchen tables? On the one hand, he’s telling us our taxes are going up; on the other, he’s telling us they’ll be frozen. On the one hand, he’s telling us we’ll get benefits; on the other, he’s saying he’s not so sure. There’s no consistency, it’s become a mystery what the party thinks about the middle class, or to be blunt, there are fewer clear financial incentives to vote SNP. And that’s a problem for a party that needs the votes of the people round my table and yours.

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The bigger context is that some of the other fundamentals of Scottish politics do not appear to be adjusting and even relatively big shifts among the middle classes may not be enough. Equally, the breakthroughs that Mr Yousaf and his comrades crave – big majorities, big support for independence – are unlikely, if not impossible, without the middle-class voters who came over to the SNP.

The problem there is that those middle-class voters are sitting at their tables and looking at their bank accounts and switching on the radio and hearing talk of taxes and the police and whatsapps and all the rest of it. And they’re saying: what does this mean? Is the SNP good for me? I’m not so sure now.