I really don’t like addressing columnists by name, especially ones I respect. But I must finally take issue with Simon Jenkins who has made, and continues to make, reckless assertions about Scotland’s share of public spending which are as offensive as they are wrong-headed. You expect bigotry from people like Kelvin MacKenzie, but not columnists in the Guardian.

“The truth of Scotland’s economy”, wrote Jenkins on Wednesday, “is that, like most of Salmond’s voters, it depends on London money and must be weaned off it.” No, Simon – the truth is that this is both ignorant and patronising.

It has always been a myth that Scots are subsidised by the English, but it has never been more of a myth than today. As the Herald points out in an analysis based on the official public expenditure figures, spending per head in Scotland is actually lower in Scotland than in London – £9,631 against £9,748. The highest spending is found in Northern Ireland, at £10,271 – but let’s not go there.

London taxes do not subsidise high Scottish spending, and those who make this claim know they are not telling the truth. The hundreds of billions in oil revenues that have flowed south over the last three decades more than outweigh any fiscal advantage enjoyed by Scots.

But even taking oil out of the equation, the argument is a fallacy. The raw tax take from Scotland at £49bn is only marginally lower than total public spending of £49.2bn. In fact, there is a strong case that, to achieve parity of services, Scottish spending should be higher than it is right now relative to England. Scotland has a third of the land mass of the British mainland with less than a tenth of the population. This means that services are more costly to administer: roads in areas with low population; schools on remote islands; hospitals in areas of multiple deprivation like Glasgow.

And what the Jock-baiters conveniently omit from the balance sheet are the colossal sums spent on infrastructure projects in London – £6bn for the Jubilee line, £9bn for the Olympics, £16bn for Crossrail – all of which are supposed to represent some tangible benefit for Scotland that somehow never makes it on to the balance sheet. Any economist will tell you that London and the south-east benefit disproportionately from “non-identifiable” spending on defence, civil administration and other functions, which makes a nonsense of any claim that the metropolis is hard done by.

I loathe this kind of politics; it is as demeaning to have to write about it as it is to have to read it. But the metropolitan press has shown an irresponsibility in its treatment of the Scottish condition in the past week that cannot and must not be allowed to continue unchallenged. London has turned into an egocentric village, obsessed with its own reflection in a self-serving media. London has persuaded itself that the rest of the country owes it a debt of gratitude for the way it gobbles up resources and debases our national culture. And it regards the rest of Britain as provincial and backward.

Scots are not fools; they can add up. They realise only too well that, as an independent nation, Scotland would be one of the wealthiest countries in the world. Scotland has suffered from generations of demographic attrition as London has sucked talent, capital and energy south, sending back a stipend delivered by the Barnett formula – a fiscal device that, contrary to that other metropolitan myth, is designed to reduce Scottish relative spending, rather than increase it.

Of course, Scots could go it alone within Europe tomorrow and thrive, but they don’t because of a sentimental and increasingly anachronistic sense of filial obligation to England. They don’t want to break things up, risk bad feeling, let emotions get out of hand. Like Robert Tressell’s ragged trousered philanthropists, they feed London their wealth and skills; keep quiet about the oil; and put up with people like MacKenzie and Jenkins – because, well, they think its the right thing to do.

The default attitude of many metropolitan commentators is that Scots should put up or shut up – well it may come to that. But if we are heading for the velvet divorce courts, then people like Simon Jenkins may be in for a shock when it comes to dividing up the assets.