Alert readers may have noticed something of a glut of articles in the press recently by right-wing commentators angrily challenging the SNP to prove its left-wing credentials if and when the new Scotland Bill ever becomes law and grants Holyrood more powers over taxation, some minor aspects of welfare and – of course – road signs.

The zenith of the phenomenon must surely be today’s eye-rubbingly bizarre Scotsman story in which the Scottish Tories urge the SNP to increase tax in order to reverse, er, Tory cuts. But there’s method behind the seeming madness.

The baton is picked up by former Scotsman hack Kenny Farquharson in the Times, who pens a harrowing account of his poverty-stricken childhood in Dundee which quickly morphs into a demand for the SNP to hike taxes to fight deprivation.

There are some curious errors and oversights in the piece. Nobody yet has a clue how “the housing element of Universal Credit” can possibly be devolved, and considerable doubt remains over whether Scottish ministers will really be able to top up existing benefits or create new ones. Just weeks ago the UK government blocked that exact measure in the Scotland Bill.

(It’s a weird point for Farquharson to raise anyway, since the Scottish Government has of course already used its existing powers to effectively scrap the bedroom tax.)

The piece goes on to make some dramatic suggestions:

Tax credits are already so complicated that almost nobody (including HMRC) really understands them. Trying to somehow jerry-build them into the Scottish tax system would be a task of such jaw-dropping difficulty, and open such a vast can of worms in terms of people moving across the border, that it would be criminally irresponsible (a) for any Scottish minister to attempt it, and (b) any UK minister to allow it.

But rather than getting bogged down in the detail, it’s perhaps worth considering the bigger picture. The principle being advocated is that however savage the Tory spending cuts handed down from Westminster, the Scottish Government should just keep ramping up taxes to mitigate them.

Clearly, the net result of that would be a massive cash drain from Scotland to London – Scots would be paying more tax in and getting less back. It’s effectively the ending of the Barnett Formula by stealth means, and it would have no end, because the UK government can always turn the screw tighter.

(Remember, the recent Budget gave Iain Duncan Smith the power to reduce the benefit cap further at any time on a whim, without even consulting Parliament.)

But there’s another aspect of the idea that the Tories will love. A Scottish Government constantly increasing taxes above those in the rest of the UK to pay for welfare would quickly find itself highly unpopular. And which party loves to stand on a tax-cutting, anti-welfare platform? Oh, there’s a coincidence.

This site has been pointing out for a long time that the Unionist parties’ devolution proposals were a trap designed to rob Scotland of money and simultaneously discredit the SNP. And because the Tories and their media allies aren’t stupid, they’ve designed it as an attack from the left, in the name of the poor.

This site has warned repeatedly since 2013 that Scotland was being set up for heavy financial punishment if it voted No. The means of that punishment are slowly but clearly taking shape, and the tone of how it will be reported in the media has been set. All that remains now is to wait for the axe to fall.