THE operation of the Barnett Formula has been barely understood for the duration of its existence since 1978 (“Sturgeon is urged to spend extra £2bn on healthcare”, The Herald, June 18).

That was under Old Barnett. Hitherto, block grant funding for Holyrood was predicated upon what was the English year-on-year increase. That, in turn, was predicated upon the then UK-wide tax regime. When English bids were supported by a tax increase, that tax increase applied also to Scotland, so that supported us getting our “share”.

But that increase was based on a straight England/Scotland population ratio of 10%, whereas we were funded by up to 20% more per head than England, so that did not cover our higher spending base; that resulted in the Barnett “squeeze”, which could have meant a £250million annual shortfall.

That read across to a lower increase in NHS funding here than in England, so that gives the impression that the SNP was holding money back from our NHS, which was not the case. So it is sheer opportunism for Scottish Conservative health spokesman Miles Briggs to make that claim and to direct the SNP to spend any extra money on healthcare. It would do that anyway; it has no other option.

What is relevant now is New Barnett. Successively, under the Calman and Smith commissions, we now have responsibility for earned income tax, the proceeds of which are now deducted in the Barnett calculation that determines the block grant.

So if Theresa May chooses to increase income tax by, say, 1p to produce £5 billion for the NHS, that would apply only to England, Wales and Northern Ireland, but not to Scotland. We do our own income tax so, to replicate the English proceeds, we, too, would have to increase our income tax to achieve our “share”. So, in that instance, Scottish Secretary David Mundell is mistaken in describing it as a “windfall” for Scotland.

But if she opted for a hike in National Insurance Contributions, that would apply also to Scotland and we would be entitled to our “share”. That would be the case, also, were VAT and/or corporation tax to be used.

The income tax example I provide would cover only year one, with the consequences knocking forward into forward years, so by year four (the Prime Minister’s target year) the extra money would remain described as £5bn per year. To reach her quoted £20bn per year extra, she would have to increase income tax by a further 1p in years two, three and four; in other words, by 4p in the pound in all.

I have ignored the question of a so-called Brexit dividend as there is a consensus that none of that would be available within the four-year term agenda. But even were it to be available, so far as Scotland is concerned, it could still not be a windfall, since it would simply be the return of our share of UK funding sent to the EU.

Douglas R Mayer,

76 Thomson Crescent, Currie.

THE SNP leadership is looking increasingly desperate as they seek to dial up the grievance, with Ian Blackford resorting in an emergency debate in the Commons to personal attacks against the Scottish Secretary and contemptuous slurs, accusing the Conservatives of being “anti-Scottish” (“Tories ‘have returned to anti-Scottish days of Margaret Thatcher’”, The Herald, June 19).

The source of all this mock outrage is the UK Government’s refusal to give Holyrood the right of veto over returning EU powers that impact on the UK as a whole. Lord Sewel, who helped to author the convention on devolution powers that takes his name, has clarified it was never intended to be used to block the ability of the UK Government to act in the best interest of the UK overall.

The SNP, of course, is annoyed that its attempts to undermine Brexit and the UK are being frustrated, but sinking deeper into a mire of political insults does nothing for its reputation amongst the public at large. SNP politicians and their hard-core supporters might egg each other on with these antics, but Scotland’s interests are the likely casualties as any hope of genuine cooperative working on Brexit is abandoned

Keith Howell,

White Moss, West Linton, Peeblesshire.

I HAVE long held the view expressed by Jim Sillars over the weekend that the First Minister is primarily to blame for the stand-off between the Scottish and the UK governments over which powers should go to Holyrood rather than Westminster after Brexit.

As Mr Sillars says, it is ludicrous for the SNP to demand powers from the Prime Minister that it would hand back to Jean-Claude Juncker.

There is an obvious logic in the controlling body of the EU administering powers that affect all of the countries in the eurozone but, surely, by the same token, there is an obvious logic in the controlling Parliament of these islands administering the powers that affect the four home countries.

Surely it would have been circumspect of the First Minister to have accepted the democratic result on Brexit (even a percentage north of the Border voted for it) and attempted to negotiate further concessions rather than try to obtain them by threats and coercion.

W MacIntyre,

32 Dunlin, East Kilbride.